Chú ý: Để đảm bảo quyền lợi và bảo vệ tài khoản của mình
Bạn hãy xác thực địa chỉ email đăng ký nhé. Chi tiết xem tại đây
Bạn hãy xác thực địa chỉ email đăng ký nhé. Chi tiết xem tại đây
{"common":{"save":0,"post_id":"6655","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6899","post_id":"6655","mon_id":"1158921","chapter_id":"1158939","question":"<p>M\u1ed9t hình ch\u1eef nh\u1eadt ABCD có chi\u1ec1u dài là AB = 15 cm và \u0111\u01b0\u1eddng chéo là<br \/>AC = 17 cm. Tính di\u1ec7n tích c\u1ee7a hình ch\u1eef nh\u1eadt ABCD.<\/p><p><span class=\"svgedit\"><svg height=\"170\" width=\"300\"> <g><title><\/title><rect fill=\"#fff\" height=\"172\" id=\"canvas_background\" width=\"302\" x=\"-1\" y=\"-1\"><\/rect> <g display=\"none\" height=\"100%\" id=\"canvasGrid\" overflow=\"visible\" width=\"100%\" x=\"0\" y=\"0\"> <rect fill=\"url(#gridpattern)\" height=\"100%\" stroke-width=\"0\" width=\"100%\" x=\"0\" y=\"0\"><\/rect> <\/g> <\/g> <g><title><\/title><g id=\"svg_7\"> <rect fill=\"#ffff56\" height=\"116\" id=\"svg_1\" stroke=\"#000\" stroke-width=\"1.5\" width=\"233.00001\" x=\"32.00001\" y=\"26.81\"><\/rect> <line fill=\"none\" id=\"svg_2\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"264.00001\" x2=\"32.00001\" y1=\"141.81\" y2=\"27.81001\"><\/line> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"24\" id=\"svg_3\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"12.00001\" xml:space=\"preserve\" y=\"26.81\">A<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"24\" id=\"svg_4\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"267.00001\" xml:space=\"preserve\" y=\"25.81\">B<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"24\" id=\"svg_5\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"270.00001\" xml:space=\"preserve\" y=\"153.81001\">C<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"24\" id=\"svg_6\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"9.00001\" xml:space=\"preserve\" y=\"155.81001\">D<\/text> <\/g> <\/g> <\/svg><\/span><\/p>","options":["<strong>A.<\/strong> S = 102 cm²","<strong>B.<\/strong> S = 130 cm²","<strong>C.<\/strong> S = 60 cm²","<strong>D.<\/strong> S = 120 cm²"],"correct":"4","level":"3","hint":"","answer":"<p>Vì tam giác ABC vuông \u1edf B nên theo \u0111\u1ecbnh lí Pythagore ta có:<\/p><p> <span class=\"math-tex\">$AB^2+BC^2=AC^2$<\/span><\/p><p>suy ra <span class=\"math-tex\">$15^2+BC^2=17^2$<\/span><\/p><p> <span class=\"math-tex\">$BC^2=17^2-15^2=64$<\/span><\/p><p>suy ra BC = 8 cm<\/p><p>Di\u1ec7n tích hình ch\u1eef nh\u1eadt ABCD là: <\/p><p>S = AB . BC = 15 . 8 = 120 cm²<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> S = 120 cm²<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-09-08 21:35:48","option_type":"txt","len":2},{"id":"6901","post_id":"6655","mon_id":"1158921","chapter_id":"1158939","question":"<p>M\u1ed9t bác th\u1ee3 mu\u1ed1n xây m\u1ed9t c\u1ea7u thang b\u1eafc t\u1eeb m\u1eb7t sàn lên sân t\u01b0\u1ee3ng cao 8 m, chân c\u1ea7u thang cách b\u1ee9c t\u01b0\u1eddng 6 m. H\u1ecfi chi\u1ec1u dài c\u1ea7u thang là bao nhiêu mét? <\/p><p><span class=\"svgedit\"><svg height=\"250\" width=\"250\"> <g><title><\/title><rect fill=\"#fff\" height=\"252\" id=\"canvas_background\" width=\"252\" x=\"-1\" y=\"-1\"><\/rect> <g display=\"none\" id=\"canvasGrid\"> <rect fill=\"url(#gridpattern)\" height=\"100%\" id=\"svg_5\" stroke-width=\"0\" width=\"100%\" x=\"0\" y=\"0\"><\/rect> <\/g> <\/g> <g><title><\/title><text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"20\" id=\"svg_8\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"217.00001\" xml:space=\"preserve\" y=\"230.81001\">C<\/text> <g id=\"svg_9\"> <rect fill=\"#7f3f00\" height=\"187.45118\" id=\"svg_1\" stroke=\"#000\" stroke-width=\"1.5\" width=\"42.29978\" x=\"27.00001\" y=\"25.85145\"><\/rect> <path d=\"m69.00441,213.07715l0,-187.45119l146.59059,187.45119l-146.59059,0z\" fill=\"#ffffff\" id=\"svg_2\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/path> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"20\" id=\"svg_3\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" transform=\"matrix(0.7293064594268798,0,0,0.9729178388025161,21.76734057955582,22.28162051120959) \" x=\"70.17486\" xml:space=\"preserve\" y=\"117.53165\">8 m<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"20\" id=\"svg_4\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" transform=\"matrix(0.7293064594268798,0,0,0.900845523283067,21.76734057955582,50.23327107545166) \" x=\"133.17486\" xml:space=\"preserve\" y=\"200.70933\">6 m<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"20\" id=\"svg_6\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"62.00001\" xml:space=\"preserve\" y=\"234.81001\">B<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"20\" id=\"svg_7\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"61.00001\" xml:space=\"preserve\" y=\"19.81\">A<\/text> <\/g> <rect fill=\"#fff\" height=\"10\" id=\"svg_10\" stroke=\"#000\" stroke-width=\"1.5\" width=\"9\" x=\"69.00001\" y=\"202.81001\"><\/rect> <\/g> <\/svg><\/span><\/p>","options":["<strong>A.<\/strong> 10 m","<strong>B.<\/strong> 11 m","<strong>C.<\/strong> 12 m","<strong>D.<\/strong> 9 m"],"correct":"1","level":"3","hint":"","answer":"<p>Vì tam giác ABC vuông \u1edf B nên theo \u0111\u1ecbnh lí Pythagore ta có:<\/p><p> <span class=\"math-tex\">$AB^2+BC^2=AC^2$<\/span><\/p><p>suy ra <span class=\"math-tex\">$8^2+6^2=AC^2$<\/span><\/p><p> <span class=\"math-tex\">$AC^2=100$<\/span><\/p><p>suy ra AC = 10 m<\/p><p>V\u1eady chi\u1ec1u dài c\u1ea7u thang là 10 m.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 10 m<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-09-08 21:39:50","option_type":"txt","len":0},{"id":"6903","post_id":"6655","mon_id":"1158921","chapter_id":"1158939","question":"<p>M\u1ed9t tam giác vuông có c\u1ea1nh huy\u1ec1n b\u1eb1ng 30 cm, \u0111\u1ed9 dài các c\u1ea1nh góc vuông t\u1ec9 l\u1ec7 v\u1edbi 3 và 4. Tính \u0111\u1ed9 dài các c\u1ea1nh góc vuông.<\/p>","options":["<strong>A.<\/strong> 14 cm, 24 cm","<strong>B.<\/strong> 18 cm, 21 cm","<strong>C.<\/strong> 18 cm, 24 cm","<strong>D.<\/strong> 12 cm, 24 cm"],"correct":"3","level":"3","hint":"","answer":"<p>G\u1ecdi \u0111\u1ed9 dài các c\u1ea1nh góc vuông là x, y (x, y > 0; \u0111\u01a1n v\u1ecb cm)<\/p><p>Theo \u0111\u1ecbnh lí Pythagore ta có: <\/p><p>x² + y² = 30² hay x² + y² = 900<\/p><p>Theo \u0111\u1ec1 bài ta có: <span class=\"math-tex\">$\\dfrac{x}{3}=\\dfrac{y}{4}$<\/span><\/p><p>suy ra <span class=\"math-tex\">$\\dfrac{x^2}{9}=\\dfrac{y^2}{16}=\\dfrac{x^2+y^2}{9+16}=\\dfrac{900}{25}=36$<\/span><\/p><p>suy ra <span class=\"math-tex\">$x^2=36.9=324$<\/span>, <span class=\"math-tex\">$y^2=36.16=576$<\/span><\/p><p>suy ra x = 18 cm và y = 24 cm.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 18 cm, 24 cm<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-09-08 21:47:30","option_type":"txt","len":1}]}