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Home Lớp 9 Toán lớp 9 - Sách Kết nối tri thức Bài 32. Hình cầuBài tập cơ bản

{"common":{"save":0,"post_id":"7993","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"11727","post_id":"7993","mon_id":"1159278","chapter_id":"1159334","question":"Hình c\u1ea7u tâm O bán kính R \u0111\u01b0\u1ee3c t\u1ea1o ra khi quay<\/p>","options":["A.<\/strong> n\u1eeda \u0111\u01b0\u1eddng tròn tâm O bán kính R quanh \u0111\u01b0\u1eddng kính c\u1ee7a nó..","B.<\/strong> tam giác vuông quanh c\u1ea1nh góc vuông.","C.<\/strong> n\u1eeda hình tròn tâm O bán kính R quanh \u0111\u01b0\u1eddng kính c\u1ee7a nó.","D.<\/strong> hình ch\u1eef nh\u1eadt quanh m\u1ed9t c\u1ea1nh c\u1ee7a nó."],"correct":"3","level":"1","hint":"","answer":"Ch\u1ecdn C.<\/strong> n\u1eeda hình tròn tâm O bán kính R quanh \u0111\u01b0\u1eddng kính c\u1ee7a nó.<\/span><\/p>Hình c\u1ea7u tâm O bán kính R \u0111\u01b0\u1ee3c t\u1ea1o ra khi quay n\u1eeda hình tròn tâm O bán kính R quanh \u0111\u01b0\u1eddng kính c\u1ee7a nó.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-05-30 07:48:01","option_type":"txt","len":3},{"id":"11729","post_id":"7993","mon_id":"1159278","chapter_id":"1159334","question":"Quan sát hình và cho bi\u1ebft bán kính hình c\u1ea7u là<\/p><svg height=\"160\" width=\"160\"> <g><title><\/title><rect fill=\"#fff\" height=\"162\" id=\"canvas_background\" width=\"162\" x=\"-1\" y=\"-1\"><\/rect> <g display=\"none\" id=\"canvasGrid\"> <rect fill=\"url(#gridpattern)\" height=\"100%\" id=\"svg_3\" stroke-width=\"0\" width=\"100%\" x=\"0\" y=\"0\"><\/rect> <\/g> <\/g> <g><title><\/title><ellipse cx=\"78.89999\" cy=\"80.15\" fill=\"#ffff56\" id=\"svg_1\" rx=\"75\" ry=\"75\" stroke=\"#000\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"79.39999\" cy=\"80.15\" fill=\"#ffff56\" id=\"svg_2\" rx=\"75.5\" ry=\"24.5\" stroke=\"#000\" stroke-width=\"1.5\"><\/ellipse> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_6\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"60.89999\" xml:space=\"preserve\" y=\"71.65\">10 cm<\/text> <path fill=\"#ffff56\" fill-opacity=\"null\" id=\"svg_8\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/path> <path d=\"m4.85095,79.41233l149.14907,0.48181c-9.41722,-36.21816 -137.89754,-41.4912 -151.00001,3.10586\" fill=\"#ffff56\" fill-opacity=\"null\" id=\"svg_9\" stroke=\"#000000\" stroke-dasharray=\"5,5\" stroke-width=\"2\"><\/path> <ellipse cx=\"78.39999\" cy=\"79.65\" fill=\"#ff0000\" id=\"svg_5\" rx=\"3.5\" ry=\"3\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/ellipse> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_10\" stroke=\"#000000\" stroke-width=\"0\" text-anchor=\"start\" x=\"56.89999\" xml:space=\"preserve\" y=\"96.65\">10 cm<\/text> <text fill=\"#000000\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_4\" stroke=\"#000\" stroke-width=\"0\" text-anchor=\"start\" x=\"72.89999\" xml:space=\"preserve\" y=\"70.65\">O<\/text> <\/g> <\/svg><\/span><\/p>","options":["A.<\/strong> 10 cm.","B.<\/strong> 5 cm.","C.<\/strong> $\\sqrt5$<\/span> cm.","D.<\/strong> 20 cm."],"correct":"2","level":"1","hint":"","answer":"Ch\u1ecdn B.<\/strong> 5 cm.<\/span><\/p>Bán kính c\u1ee7a hình c\u1ea7u là R = $\\dfrac{10}{2}$<\/span> = 5 cm.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-05-30 07:56:55","option_type":"math","len":0},{"id":"11731","post_id":"7993","mon_id":"1159278","chapter_id":"1159334","question":"Khi c\u1eaft hình c\u1ea7u tâm O bán kính R b\u1edfi m\u1ed9t m\u1eb7t ph\u1eb3ng b\u1ea5t k\u1ef3 thì m\u1eb7t c\u1eaft thu \u0111\u01b0\u1ee3c luôn là m\u1ed9t<\/p>","options":["A.<\/strong> \u0111\u01b0\u1eddng tròn.","B.<\/strong> hình vuông","C.<\/strong> hình ch\u1eef nh\u1eadt.","D.<\/strong> hình tròn."],"correct":"4","level":"1","hint":"","answer":"Ch\u1ecdn D.<\/strong> hình tròn.<\/span><\/p>Khi c\u1eaft hình c\u1ea7u tâm O bán kính R b\u1edfi m\u1ed9t m\u1eb7t ph\u1eb3ng b\u1ea5t k\u1ef3 thì m\u1eb7t c\u1eaft thu \u0111\u01b0\u1ee3c luôn là m\u1ed9t hình tròn.<\/p><svg height=\"170\" width=\"280\"> <g><title><\/title><rect fill=\"#ffffff\" height=\"172\" id=\"canvas_background\" width=\"282\" 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_20\"> <ellipse cx=\"144.89999\" cy=\"86.15\" fill=\"#ffffff\" id=\"svg_1\" rx=\"78\" ry=\"78.5\" stroke=\"#000\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"144.39999\" cy=\"55.65\" fill=\"none\" fill-opacity=\"null\" id=\"svg_2\" rx=\"71.5\" ry=\"15\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"92.39999\" cy=\"45.15\" fill=\"#ffffff\" id=\"svg_5\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"109.39999\" cy=\"42.15\" fill=\"#ffffff\" id=\"svg_6\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"128.39999\" cy=\"41.15\" fill=\"#ffffff\" id=\"svg_7\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"146.39999\" cy=\"41.15\" fill=\"#ffffff\" id=\"svg_9\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"163.39999\" cy=\"41.15\" fill=\"#ffffff\" id=\"svg_10\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"182.39999\" cy=\"43.15\" fill=\"#ffffff\" id=\"svg_11\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"200.39999\" cy=\"47.15\" fill=\"#ffffff\" id=\"svg_12\" rx=\"3.5\" ry=\"3.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <path d=\"m8.2005,88.76008l52.2,-65.99999l208.79999,0l-52.2,65.99999l-208.79999,0z\" fill=\"none\" id=\"svg_13\" stroke=\"#000000\" stroke-width=\"1.5\"><\/path> <line fill=\"none\" id=\"svg_14\" stroke=\"#ffffff\" stroke-dasharray=\"5,5\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-width=\"2\" x1=\"104.89999\" x2=\"180.89999\" y1=\"22.65\" y2=\"22.65\"><\/line> <ellipse cx=\"69.39999\" cy=\"66.15\" fill=\"#ffffff\" id=\"svg_16\" rx=\"2.5\" ry=\"2.5\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"68.39999\" cy=\"77.15\" fill=\"#ffffff\" id=\"svg_17\" rx=\"2.5\" ry=\"2.5\" stroke=\"#e5e5e5\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"218.89999\" cy=\"62.65\" fill=\"#ffffff\" id=\"svg_18\" rx=\"3\" ry=\"2\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <ellipse cx=\"218.89999\" cy=\"73.65\" fill=\"#ffffff\" id=\"svg_19\" rx=\"3\" ry=\"2\" stroke=\"#ffffff\" stroke-width=\"1.5\"><\/ellipse> <\/g> <\/g> <\/svg><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-05-30 08:06:25","option_type":"txt","len":2}]}