{"id":14377,"date":"2025-06-08T05:50:42","date_gmt":"2025-06-07T22:50:42","guid":{"rendered":"https:\/\/www.ckconitsha.com\/vn\/?p=14377"},"modified":"2025-07-04T18:30:08","modified_gmt":"2025-07-04T11:30:08","slug":"cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen","status":"publish","type":"post","link":"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/","title":{"rendered":"C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch h\u00ecnh tr\u00f2n l\u1edbp 5 v\u00e0 b\u00e0i t\u1eadp t\u1ef1 luy\u1ec7n"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Xem_lai_kien_%E2%80%8B%E2%80%8Bthuc_ve_vong_tron_lop_5\" >Xem l\u1ea1i ki\u1ebfn \u200b\u200bth\u1ee9c v\u1ec1 v\u00f2ng tr\u00f2n l\u1edbp 5<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Dinh_nghia_cua_vong_tron_va_vong_tron\" >\u0110\u1ecbnh ngh\u0129a c\u1ee7a v\u00f2ng tr\u00f2n v\u00e0 v\u00f2ng tr\u00f2n<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Tinh_chat_cua_vong_tron\" >T\u00ednh ch\u1ea5t c\u1ee7a v\u00f2ng tr\u00f2n<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Cong_thuc_tinh_toan_khu_vuc_vong_tron_thu_5\" >C\u00f4ng th\u1ee9c t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng tr\u00f2n th\u1ee9 5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Cac_buoc_chi_tiet_de_tinh_dien_tich_cua_lop_5\" >C\u00e1c b\u01b0\u1edbc chi ti\u1ebft \u0111\u1ec3 t\u00ednh di\u1ec7n t\u00edch c\u1ee7a l\u1edbp 5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Dap_an_Khu_vuc_tap_the_duc_Lop_5_SGK\" >\u0110\u00e1p \u00e1n Khu v\u1ef1c t\u1eadp th\u1ec3 d\u1ee5c L\u1edbp 5 (SGK)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Bai_1_Trang_100_Toan_hoc_lop_5_SGK\" >B\u00e0i 1, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Bai_2_Trang_100_Toan_hoc_lop_5_SGK\" >B\u00e0i 2, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Bai_3_Trang_100_Toan_hoc_lop_5_SGK\" >B\u00e0i 3, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.ckconitsha.com\/vn\/cong-thuc-tinh-dien-tich-hinh-tron-lop-5-va-bai-tap-tu-luyen\/#Mot_so_bai_tap_tu_dong_tren_khu_vuc_Vong_tron_lop_5_co_cau_tra_loi\" >M\u1ed9t s\u1ed1 b\u00e0i t\u1eadp t\u1ef1 \u0111\u1ed9ng tr\u00ean khu v\u1ef1c V\u00f2ng tr\u00f2n l\u1edbp 5 (c\u00f3 c\u00e2u tr\u1ea3 l\u1eddi)<\/a><\/li><\/ul><\/nav><\/div>\n<\/p>\n<p>Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang t\u00f4i s\u1ebd kh\u00e1m ph\u00e1 c\u00e1ch t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng tr\u00f2n m\u1ed9t c\u00e1ch d\u1ec5 d\u00e0ng v\u00e0 h\u1ee3p l\u00fd cho h\u1ecdc sinh l\u1edbp 5. Kh\u1ec9 s\u1ebd b\u1eaft \u0111\u1ea7u v\u1edbi c\u00f4ng th\u1ee9c c\u01a1 b\u1ea3n \u0111\u1ec3 t\u00ednh to\u00e1n di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u00e0 \u00e1p d\u1ee5ng n\u00f3 v\u00e0o c\u00e1c b\u00e0i t\u1eadp th\u1ef1c t\u1ebf. B\u00ean c\u1ea1nh \u0111\u00f3, c\u0169ng s\u1ebd c\u00f3 m\u1ed9t s\u1ed1 b\u00e0i t\u1eadp t\u1ef1 l\u01b0u tr\u1eef \u0111\u1ec3 gi\u00fap b\u1ea1n l\u00e0m ch\u1ee7 ki\u1ebfn \u200b\u200bth\u1ee9c v\u00e0 r\u00e8n k\u1ef9 n\u0103ng t\u00ednh to\u00e1n. Kh\u00e1m ph\u00e1 ki\u1ebfn \u200b\u200bth\u1ee9c v\u1ec1 khu v\u1ef1c v\u00f2ng tr\u00f2n l\u1edbp 5 b\u00ean d\u01b0\u1edbi!<\/p>\n<p>                        Xem t\u1ea5t c\u1ea3<\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Xem_lai_kien_%E2%80%8B%E2%80%8Bthuc_ve_vong_tron_lop_5\"><\/span>Xem l\u1ea1i ki\u1ebfn \u200b\u200bth\u1ee9c v\u1ec1 v\u00f2ng tr\u00f2n l\u1edbp 5<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">Tr\u01b0\u1edbc khi \u0111i v\u00e0o c\u00e1ch t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng tr\u00f2n th\u1ee9 5, ch\u00fang ta c\u1ea7n l\u1eb7p l\u1ea1i m\u1ed9t s\u1ed1 ki\u1ebfn \u200b\u200bth\u1ee9c v\u1ec1 v\u00f2ng tr\u00f2n, bao g\u1ed3m: \u0111\u1ecbnh ngh\u0129a v\u00e0 thu\u1ed9c t\u00ednh, ngay b\u00ean d\u01b0\u1edbi.<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dinh_nghia_cua_vong_tron_va_vong_tron\"><\/span>\u0110\u1ecbnh ngh\u0129a c\u1ee7a v\u00f2ng tr\u00f2n v\u00e0 v\u00f2ng tr\u00f2n<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">M\u1ed9t v\u00f2ng tr\u00f2n l\u00e0 g\u00ec? V\u00f2ng tr\u00f2n \u0111\u01b0\u1ee3c hi\u1ec3u \u0111\u01a1n gi\u1ea3n l\u00e0 m\u1ed9t v\u00f2ng tr\u00f2n xung quanh v\u00f2ng tr\u00f2n. N\u00f3 \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh b\u1edfi m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c \u0111i\u1ec3m trong c\u00f9ng m\u1ed9t m\u1eb7t ph\u1eb3ng, \u0111\u1eb7t m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh (\u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 t\u00e2m tr\u00ed) l\u00e0 kho\u1ea3ng c\u00e1ch kh\u00f4ng \u0111\u1ed5i (\u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 b\u00e1n k\u00ednh). C\u1ee5 th\u1ec3, b\u00e1n k\u00ednh \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u l\u00e0 R.<\/p>\n<p dir=\"ltr\">M\u1ed9t v\u00f2ng tr\u00f2n l\u00e0 g\u00ec? V\u00f2ng tr\u00f2n trong to\u00e1n h\u1ecdc \u0111\u01b0\u1ee3c hi\u1ec3u l\u00e0 khu v\u1ef1c m\u00e1y bay b\u1ecb gi\u1edbi h\u1ea1n b\u1edfi m\u1ed9t v\u00f2ng tr\u00f2n (bao g\u1ed3m c\u1ea3 b\u00ean trong v\u00e0 \u0111\u01b0\u1eddng vi\u1ec1n). \u0110\u1eb7c bi\u1ec7t, trung t\u00e2m &#8211; b\u00e1n k\u00ednh &#8211; chu vi c\u1ee7a v\u00f2ng tr\u00f2n c\u0169ng l\u00e0 trung t\u00e2m &#8211; b\u00e1n k\u00ednh &#8211; chu vi c\u1ee7a v\u00f2ng tr\u00f2n xung quanh.<\/p>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/1-dien-tich-hinh-tron-lop-5.png\" alt=\"M\u1ed9t v\u00f2ng tr\u00f2n l\u00e0 g\u00ec? M\u1ed9t v\u00f2ng tr\u00f2n l\u00e0 g\u00ec? (\u1ea2nh: B\u1ed9 s\u01b0u t\u1eadp Internet)\" width=\"100%\"><\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Tinh_chat_cua_vong_tron\"><\/span>T\u00ednh ch\u1ea5t c\u1ee7a v\u00f2ng tr\u00f2n<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">M\u1ed9t s\u1ed1 thu\u1ed9c t\u00ednh c\u1ee7a v\u00f2ng tr\u00f2n m\u00e0 b\u1ea1n c\u1ea7n nh\u1edb:<\/p>\n<ol>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">\u0110\u1ed9 \u0111\u1ed1i x\u1ee9ng c\u1ee7a v\u00f2ng tr\u00f2n: N\u1ebfu v\u1ebd m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng t\u1eeb t\u00e2m c\u1ee7a v\u00f2ng tr\u00f2n \u0111\u1ebfn b\u1ea5t k\u1ef3 \u0111i\u1ec3m n\u00e0o tr\u00ean \u0111\u01b0\u1eddng vi\u1ec1n, \u0111\u01b0\u1eddng l\u00e0 tr\u1ee5c \u0111\u1ed1i x\u1ee9ng c\u1ee7a v\u00f2ng tr\u00f2n. (V\u00f2ng tr\u00f2n c\u0169ng \u0111\u1ed1i x\u1ee9ng.)<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">T\u1ea5t c\u1ea3 c\u00e1c v\u00f2ng tr\u00f2n l\u00e0 t\u01b0\u01a1ng t\u1ef1 nhau (v\u1edbi c\u00f9ng h\u00ecnh d\u1ea1ng v\u00e0 c\u00e1c thu\u1ed9c t\u00ednh t\u01b0\u01a1ng t\u1ef1).<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Chu vi c\u1ee7a v\u00f2ng tr\u00f2n t\u1ef7 l\u1ec7 thu\u1eadn v\u1edbi b\u00e1n k\u00ednh, v\u1edbi h\u1eb1ng s\u1ed1 2\u03c0. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 n\u1ebfu b\u1ea1n t\u0103ng g\u1ea5p \u0111\u00f4i b\u00e1n k\u00ednh, chu vi c\u0169ng s\u1ebd t\u0103ng g\u1ea5p \u0111\u00f4i.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n t\u1ef7 l\u1ec7 thu\u1eadn v\u1edbi b\u00e1n k\u00ednh vu\u00f4ng, v\u1edbi h\u1eb1ng s\u1ed1 \u03c0. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 n\u1ebfu b\u1ea1n t\u0103ng g\u1ea5p \u0111\u00f4i b\u00e1n k\u00ednh, khu v\u1ef1c n\u00e0y s\u1ebd t\u0103ng b\u1ed1n l\u1ea7n.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">V\u00f2ng tr\u00f2n \u0111\u01a1n v\u1ecb l\u00e0 m\u1ed9t v\u00f2ng tr\u00f2n c\u00f3 trung t\u00e2m \u1edf g\u1ed1c v\u00e0 b\u00e1n k\u00ednh 1.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Th\u00f4ng qua ba \u0111i\u1ec3m kh\u00f4ng \u0111\u01b0\u1ee3c c\u0103n ch\u1ec9nh, lu\u00f4n c\u00f3 m\u1ed9t v\u00f2ng tr\u00f2n \u0111i qua c\u1ea3 ba \u0111i\u1ec3m.<\/p>\n<\/li>\n<\/ol>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/2-dien-tich-hinh-tron-lop-5.png\" alt=\"T\u00ednh ch\u1ea5t c\u1ee7a h\u00ecnh tr\u00f2n. (\u1ea2nh: B\u1ed9 s\u01b0u t\u1eadp Internet)\" width=\"100%\"><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Cong_thuc_tinh_toan_khu_vuc_vong_tron_thu_5\"><\/span>C\u00f4ng th\u1ee9c t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng tr\u00f2n th\u1ee9 5<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">C\u00f3 hai c\u00f4ng th\u1ee9c c\u01a1 b\u1ea3n c\u1ea7n nh\u1edb khi n\u00f3i \u0111\u1ebfn v\u00f2ng tr\u00f2n, bao g\u1ed3m: khu v\u1ef1c v\u00e0 chu vi.<\/p>\n<p dir=\"ltr\">D\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u00f4ng th\u1ee9c t\u00ednh to\u00e1n di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">S = \u03c0.rr<\/p>\n<p dir=\"ltr\">Trong \u0111\u00f3:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">S: Khu v\u1ef1c c\u1ee7a v\u00f2ng tr\u00f2n<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">\u03c0 (pi) ~ 3,14<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">D: \u0110\u01b0\u1eddng k\u00ednh tr\u00f2n<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">R: B\u00e1n k\u00ednh (R = D\/2)<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\">Ngo\u00e0i ra, b\u1ea1n c\u0169ng c\u1ea7n nh\u1edb c\u00f4ng th\u1ee9c t\u00ednh to\u00e1n chu vi c\u1ee7a L\u1edbp 5, nh\u01b0 sau:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">C = 2.\u03c0.r = \u03c0.d<\/p>\n<p dir=\"ltr\">Trong \u0111\u00f3:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">C: chu vi c\u1ee7a v\u00f2ng tr\u00f2n<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">\u03c0 (pi) ~ 3,14<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">D: \u0110\u01b0\u1eddng k\u00ednh<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">R: B\u00e1n k\u00ednh (R = D\/2)<\/p>\n<\/li>\n<\/ul>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Cac_buoc_chi_tiet_de_tinh_dien_tich_cua_lop_5\"><\/span>C\u00e1c b\u01b0\u1edbc chi ti\u1ebft \u0111\u1ec3 t\u00ednh di\u1ec7n t\u00edch c\u1ee7a l\u1edbp 5<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">B\u01b0\u1edbc 1: \u0110\u1ecdc k\u1ef9 v\u1ea5n \u0111\u1ec1 v\u00e0 ki\u1ec3m tra d\u1eef li\u1ec7u c\u1ea7n thi\u1ebft (ch\u1eb3ng h\u1ea1n nh\u01b0: d, r, &#8230;)<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Trong tr\u01b0\u1eddng h\u1ee3p \u0111\u1ee7 d\u1eef li\u1ec7u, l\u1eafp r\u00e1p \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u01b0a v\u00e0o c\u00f4ng th\u1ee9c t\u00ednh to\u00e1n.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Trong tr\u01b0\u1eddng h\u1ee3p kh\u00f4ng \u0111\u1ee7 d\u1eef li\u1ec7u, ti\u1ebfp t\u1ee5c b\u01b0\u1edbc 2.<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\">B\u01b0\u1edbc 2: T\u00ecm d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Trong tr\u01b0\u1eddng h\u1ee3p c\u00f3 v\u1ea5n \u0111\u1ec1 cho d -&gt; T\u00ednh R = D\/2<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Trong tr\u01b0\u1eddng h\u1ee3p v\u1ea5n \u0111\u1ec1 cho c -&gt; T\u00ednh R = C\/(2.\u03c0)<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\">B\u01b0\u1edbc 3: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n c\u1ee7a L\u1edbp 5, theo c\u00f4ng th\u1ee9c S = \u03c0.RR<\/p>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/3-dien-tich-hinh-tron-lop-5.png\" alt=\"C\u00e1c b\u01b0\u1edbc \u0111\u1ec3 t\u00ednh to\u00e1n khu v\u1ef1c c\u1ee7a l\u1edbp 5. (\u1ea2nh: B\u1ed9 s\u01b0u t\u1eadp Internet)\" width=\"100%\"><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dap_an_Khu_vuc_tap_the_duc_Lop_5_SGK\"><\/span>\u0110\u00e1p \u00e1n Khu v\u1ef1c t\u1eadp th\u1ec3 d\u1ee5c L\u1edbp 5 (SGK)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_1_Trang_100_Toan_hoc_lop_5_SGK\"><\/span>B\u00e0i 1, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">Ch\u1ee7 \u0111\u1ec1: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u1edbi b\u00e1n k\u00ednh r<\/p>\n<p dir=\"ltr\">a) r = 5cm<\/p>\n<p dir=\"ltr\">b) r = 0,4dm<\/p>\n<p dir=\"ltr\">c) r = 3\/5m<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi:<\/p>\n<p dir=\"ltr\"><em>(\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c S = \u03c0.RR cho t\u1ea5t c\u1ea3 c\u00e1c c\u00e2u.)<\/em><\/p>\n<p dir=\"ltr\">a) Khu v\u1ef1c c\u1ee7a v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">5 x 5 x 3.14 = 78,5 (cm2)<\/p>\n<p dir=\"ltr\">b) Khu v\u1ef1c c\u1ee7a v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">0,4 x 0,4 x 3,14 = 0,5024 (DM2)<\/p>\n<p dir=\"ltr\">c) Khu v\u1ef1c c\u1ee7a v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">3\/5 x 3\/5 x 3.14 = 1.1304 (m2)<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_2_Trang_100_Toan_hoc_lop_5_SGK\"><\/span>B\u00e0i 2, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">Ch\u1ee7 \u0111\u1ec1: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n c\u00f3 \u0111\u01b0\u1eddng k\u00ednh d<\/p>\n<p dir=\"ltr\">A) D = 12cm<\/p>\n<p dir=\"ltr\">B) D = 7.2dm<\/p>\n<p dir=\"ltr\">c) d = 4\/5m<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi:<\/p>\n<p dir=\"ltr\"><em>(T\u00ednh R = D\/2, sau \u0111\u00f3 \u00e1p d\u1ee5ng c\u00f4ng th\u1ee9c S = \u03c0.RR cho t\u1ea5t c\u1ea3 c\u00e1c c\u00e2u.)<\/em><\/p>\n<p dir=\"ltr\">a) B\u00e1n k\u00ednh v\u00f2ng tr\u00f2n d\u00e0i:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">12: 2 = 6 (cm)<\/p>\n<p dir=\"ltr\">Khu v\u1ef1c v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">6 x 6 x 3.14 = 113.04 (cm2)<\/p>\n<p dir=\"ltr\">b) B\u00e1n k\u00ednh v\u00f2ng tr\u00f2n d\u00e0i:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">7.2: 2 = 3.6 (DM)<\/p>\n<p dir=\"ltr\">Khu v\u1ef1c v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">3,6 x 3,6 x 3.14 = 40,6944 (DM2)<\/p>\n<p dir=\"ltr\">C) B\u00e1n k\u00ednh v\u00f2ng tr\u00f2n d\u00e0i:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">4\/5: 2 = 0,4 (m)<\/p>\n<p dir=\"ltr\">Khu v\u1ef1c v\u00f2ng tr\u00f2n l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">0,4 x 0,4 x 3,14 = 0,5024 (m2)<\/p>\n<p dir=\"ltr\" style=\"text-align: left\">\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_3_Trang_100_Toan_hoc_lop_5_SGK\"><\/span>B\u00e0i 3, Trang 100, To\u00e1n h\u1ecdc l\u1edbp 5 (SGK)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">Ch\u1ee7 \u0111\u1ec1: T\u00ecm di\u1ec7n t\u00edch c\u1ee7a m\u1ed9t b\u1ea3ng tr\u00f2n c\u00f3 b\u00e1n k\u00ednh 45cm<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">Theo ch\u1ee7 \u0111\u1ec1, ch\u00fang ta c\u00f3 r = 45<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">Di\u1ec7n t\u00edch b\u1ec1 m\u1eb7t b\u00e0n \u0111\u00f3 l\u00e0:<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">45 x 45 x 3.14 = 6358.5 (cm2)<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">6358,5 cm2 = 63,585 DM2<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">Tr\u1ea3 l\u1eddi: 63,585 DM2<\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Mot_so_bai_tap_tu_dong_tren_khu_vuc_Vong_tron_lop_5_co_cau_tra_loi\"><\/span>M\u1ed9t s\u1ed1 b\u00e0i t\u1eadp t\u1ef1 \u0111\u1ed9ng tr\u00ean khu v\u1ef1c V\u00f2ng tr\u00f2n l\u1edbp 5 (c\u00f3 c\u00e2u tr\u1ea3 l\u1eddi)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">B\u00e0i 1: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u1edbi b\u00e1n k\u00ednh 3 cm.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: S = \u03c0 \u00d7 3 cm \u00d7 3 cm = 28,26 cm2 (l\u00e0m tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<p dir=\"ltr\">B\u00e0i 2: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u1edbi b\u00e1n k\u00ednh 7 m.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: S = \u03c0 \u00d7 7 m \u00d7 7 m = 153,94 m2 (l\u00e0m tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<table style=\"border-collapse: collapse;width: 100.01%;background-color: #fbeeb8\" border=\"1\">\n<tr>\n<td style=\"width: 98.5932%\">\n<p style=\"text-align: center\">\u0110\u1eebng b\u1ecf l\u1ee1 !!<\/p>\n<p style=\"text-align: center\">Ch\u01b0\u01a1ng tr\u00ecnh to\u00e1n h\u1ecdc b\u1eb1ng ti\u1ebfng Anh, gi\u00fap ph\u00e1t tri\u1ec3n t\u01b0 duy theo c\u00e1ch to\u00e0n di\u1ec7n nh\u1ea5t.<\/p>\n<p style=\"text-align: center\">Nh\u1eadn t\u1ed1i \u0111a 40% \u01b0u \u0111\u00e3i ngay t\u1ea1i \u0111\u00e2y!<img decoding=\"async\" style=\"margin-left: auto;margin-right: auto\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/taimienphiMM.png\" width=\"185\"><\/p>\n<\/td>\n<\/tr>\n<\/table>\n<p dir=\"ltr\">B\u00e0i 3: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n c\u00f3 \u0111\u01b0\u1eddng k\u00ednh 10 cm.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: <\/p>\n<p dir=\"ltr\">Do \u0111\u01b0\u1eddng k\u00ednh g\u1ea5p \u0111\u00f4i \u0111\u01b0\u1eddng k\u00ednh c\u1ee7a b\u00e1n k\u00ednh, b\u00e1n k\u00ednh l\u00e0 10 cm: 2 = 5 cm.<\/p>\n<p dir=\"ltr\">S = \u03c0 \u00d7 5 cm \u00d7 5 cm = 78,54 cm2 (l\u00e0m tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<p dir=\"ltr\">B\u00e0i 4: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n c\u00f3 \u0111\u01b0\u1eddng k\u00ednh 14 m.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: <\/p>\n<p dir=\"ltr\">V\u00ec \u0111\u01b0\u1eddng k\u00ednh g\u1ea5p \u0111\u00f4i \u0111\u01b0\u1eddng k\u00ednh c\u1ee7a b\u00e1n k\u00ednh, b\u00e1n k\u00ednh l\u00e0 14 m: 2 = 7 m.<\/p>\n<p dir=\"ltr\">S = \u03c0 \u00d7 7 m \u00d7 7 m = 153,94 m2 (l\u00e0m tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<p dir=\"ltr\">B\u00e0i 5: Bi\u1ebft di\u1ec7n t\u00edch v\u00f2ng tr\u00f2n l\u00e0 50,24 cm2, t\u00ednh to\u00e1n b\u00e1n k\u00ednh c\u1ee7a v\u00f2ng tr\u00f2n.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: \u0110\u1ec3 t\u00ednh to\u00e1n b\u00e1n k\u00ednh, ch\u00fang t\u00f4i s\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c s = \u03c0 \u00d7 r \u00d7 r v\u00e0 thay th\u1ebf gi\u00e1 tr\u1ecb di\u1ec7n t\u00edch \u0111\u00e3 cho.<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">50,24 cm^2 = \u03c0 \u00d7 r \u00d7 r<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">r^2 = 50,24 cm^2 \u00f7 \u03c0<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">r^2 \u2248 16 cm^2<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">R \u2248 \u221a16 cm<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">R \u2248 4 cm<\/p>\n<p dir=\"ltr\" style=\"text-align: left\">Xem th\u00eam:<\/p>\n<ol>\n<li dir=\"ltr\" style=\"text-align: left\">Shining Home &#8211; Gia \u0111\u00ecnh Anh Ng\u1eef Math &#8211; \u1ee8ng d\u1ee5ng to\u00e1n h\u1ecdc b\u1eb1ng ti\u1ebfng Anh s\u1ed1 1 cho tr\u1ebb m\u1eabu gi\u00e1o &amp; tr\u01b0\u1eddng ti\u1ec3u h\u1ecdc<\/li>\n<li dir=\"ltr\" style=\"text-align: left\">Kim c\u01b0\u01a1ng l\u1edbp 4 v\u00e0 ki\u1ebfn \u200b\u200bth\u1ee9c m\u00e0 h\u1ecdc sinh ph\u1ea3i ghi nh\u1edb<\/li>\n<\/ol>\n<p dir=\"ltr\">B\u00e0i 6: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u1edbi chu vi 18 cm.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: <\/p>\n<p dir=\"ltr\">\u0110\u1ec3 t\u00ednh to\u00e1n khu v\u1ef1c, ch\u00fang ta c\u1ea7n bi\u1ebft b\u00e1n k\u00ednh. V\u00ec chu vi (c) = 2.\u03c0.r, r = c: (2\u03c0) = 18 cm: (2 \u00d7 3,14) 2,87 cm.<\/p>\n<p dir=\"ltr\">S = \u03c0 \u00d7 (2,87 cm) \u00d7 (2,87 cm) \u2248 25,94 cm2 (tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<p dir=\"ltr\">B\u00e0i 7: T\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u1edbi chu vi 36 m.<\/p>\n<p dir=\"ltr\">Tr\u1ea3 l\u1eddi: <\/p>\n<p dir=\"ltr\">\u0110\u1ec3 t\u00ednh to\u00e1n khu v\u1ef1c, ch\u00fang ta c\u1ea7n bi\u1ebft b\u00e1n k\u00ednh. V\u00ec chu vi (c) = 2.\u03c0.r, r = c \u00f7 (2\u03c0) = 36 m: (2 \u00d7 3,14) \u2248 5,73 m.<\/p>\n<p dir=\"ltr\">S = \u03c0 \u00d7 (5,73 m) \u00d7 (5,73 m) \u2248 103,18 m2 (tr\u00f2n 2 s\u1ed1 th\u1eadp ph\u00e2n).<\/p>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/4-dien-tich-hinh-tron-lop-5.png\" alt=\"C\u00e1ch t\u00ednh di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n l\u1edbp 5. (\u1ea2nh: B\u1ed9 s\u01b0u t\u1eadp Internet)\" width=\"100%\"><\/p>\n<\/p>\n<p dir=\"ltr\">Tr\u00ean \u0111\u00e2y l\u00e0 to\u00e0n b\u1ed9 n\u1ed9i dung c\u1ee7a c\u00f4ng th\u1ee9c t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng 5 m\u00e0 kh\u1ec9 mu\u1ed1n chia s\u1ebb v\u1edbi b\u1ea1n. Vui l\u00f2ng l\u01b0u v\u00e0 th\u1ef1c h\u00e0nh th\u01b0\u1eddng xuy\u00ean \u0111\u1ec3 c\u1ea3i thi\u1ec7n kh\u1ea3 n\u0103ng to\u00e1n h\u1ecdc c\u1ee7a b\u1ea1n!<\/p>\n<p>Ngu\u1ed3n: <a href=\"https:\/\/www.ckconitsha.com\/vn\/\">https:\/\/www.ckconitsha.com\/vn\/<\/a> T\u00e1c gi\u1ea3: <a href=\"https:\/\/www.ckconitsha.com\/vn\/author\/nguyenlandung\">Nguy\u1ec5n L\u00e2n d\u0169ng<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang t\u00f4i s\u1ebd kh\u00e1m ph\u00e1 c\u00e1ch t\u00ednh to\u00e1n khu v\u1ef1c v\u00f2ng tr\u00f2n m\u1ed9t c\u00e1ch d\u1ec5 d\u00e0ng v\u00e0 h\u1ee3p l\u00fd cho h\u1ecdc sinh l\u1edbp 5. Kh\u1ec9 s\u1ebd b\u1eaft \u0111\u1ea7u v\u1edbi c\u00f4ng th\u1ee9c c\u01a1 b\u1ea3n \u0111\u1ec3 t\u00ednh to\u00e1n di\u1ec7n t\u00edch c\u1ee7a v\u00f2ng tr\u00f2n v\u00e0 \u00e1p d\u1ee5ng n\u00f3 v\u00e0o c\u00e1c b\u00e0i t\u1eadp th\u1ef1c t\u1ebf&#8230;.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[100],"tags":[],"class_list":["post-14377","post","type-post","status-publish","format-standard","hentry","category-kien-thuc"],"_links":{"self":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14377","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/comments?post=14377"}],"version-history":[{"count":2,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14377\/revisions"}],"predecessor-version":[{"id":17372,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14377\/revisions\/17372"}],"wp:attachment":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/media?parent=14377"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/categories?post=14377"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/tags?post=14377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}