Ôn tập chương 8 Những hình hình học cơ bản

Home Toán lớp 6 Tập 2 Những hình hình học cơ bản Ôn tập chương 8Bài tập nâng cao

{"common":{"save":0,"post_id":"4686","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7420","post_id":"4686","mon_id":"1158113","chapter_id":"1158164","question":"Cho \u0111i\u1ec3m H n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m J và K nh\u01b0 hình v\u1ebd.<\/p>Bi\u1ebft JK = 6.HK và JH = 15 cm.<\/p>Tính \u0111\u1ed9 dài \u0111o\u1ea1n th\u1eb3ng JK.<\/p><svg height=\"105\" width=\"200\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\"> <g><title><\/title><rect fill=\"#fff\" height=\"107\" id=\"canvas_background\" width=\"202\" 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><image height=\"71\" id=\"svg_1\" width=\"194\" x=\"4\" xlink:href=\"data:image\/png;base64,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\" y=\"27.5\"><\/image> <path d=\"m83.32966,-13.1068c0,-12.13735 -1.20796,-19.61928 -5.69469,-21.11566l0.11504,-0.33253c6.5,0.33253 8.28319,5.98554 8.28319,24.10843l0,25.10602c0,11.13976 0.40265,16.46024 4.60177,19.45301l0,0.33253c-4.14159,2.99277 -4.60177,8.31325 -4.60177,19.28675l0,26.76867c0,17.45783 -2.24336,22.44578 -8.28319,22.94458l-0.11504,-0.3317c4.60177,-1.99518 5.69469,-8.64578 5.69469,-21.28276l0,-26.76867c0,-11.30602 0.5177,-17.79036 4.83186,-20.61687l0,-0.33253c-4.37168,-2.99277 -4.83186,-9.9759 -4.83186,-21.28193l0,-25.93735z\" fill=\"#fff\" id=\"svg_2\" stroke=\"#000\" stroke-width=\"1.5\" transform=\"rotate(-90 84.13497161865236,34.44500732421876) \"><\/path> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"18\" id=\"svg_3\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"64\" xml:space=\"preserve\" y=\"24\">15 cm<\/text> <\/g> <\/svg><\/span><\/p>JK = <input class=\"tim_x input_number\" tpl=\"dien_so\" type=\"text\"\/> cm.<\/strong><\/p>","options":"","correct":["[\"18\"]"],"level":"3","hint":"\u0110\u1eb7t HK = x (cm) v\u1edbi x > 0.<\/p>Khi \u0111ó JK = 6.HK = 6.x<\/p>Thay vào bi\u1ec3u th\u1ee9c JK = HJ + HK, ta \u0111\u01b0\u1ee3c 6.x = 15 + x<\/p>Tìm x s\u1ebd tính \u0111\u01b0\u1ee3c \u0111\u1ed9 dài JK.<\/p>","answer":"\u0110\u1eb7t HK = x (cm) v\u1edbi x > 0.<\/p>Vì JK = 6.HK nên JK = 6.x<\/p>Vì H n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m J và K nên    JK = HJ + HK<\/p>                                                   Hay  6.x = 15 + x     (vì JK = 6.x, HJ = 15 mm, HK = x)<\/p>                                                       6.x - x = 15     (chuy\u1ec3n x qua v\u1ebf trái thì ph\u1ea3i \u0111\u1ed5i d\u1ea5u)<\/p>                                                            5.x = 15        <\/p>                                                               x = 15 : 5           <\/p>                                                               x = 3<\/p>Mà JK = 6.x = 6 . 3 = 18 (cm)<\/span><\/p>S\u1ed1 c\u1ea7n \u0111i\u1ec1n là 18<\/strong><\/span>                                                <\/p>","type":"blank","extra_type":"","time":"0","user_id":"131","test":"3","date":"2021-09-09 13:47:07"},{"id":"7423","post_id":"4686","mon_id":"1158113","chapter_id":"1158164","question":"Cho ba \u0111i\u1ec3m H, J, K th\u1eb3ng hàng, trong \u0111ó H n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m J và K. G\u1ecdi G là trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng JH và S là trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng HK. Bi\u1ebft JK = 46 cm, tính \u0111\u1ed9 dài \u0111o\u1ea1n th\u1eb3ng GS.<\/p>","options":["GS = 23 mm","GS = 23 cm","GS = 23 dm","GS = 23 m"],"correct":"2","level":"3","hint":"V\u1ebd hình.<\/p>Ta có:    JK = JH + HK mà JH = 2 GH (G là trung \u0111i\u1ec3m c\u1ee7a JH), HK = 2 HS (S là trung \u0111i\u1ec3m c\u1ee7a HK)<\/p>Suy ra:  JK = 2 GH + 2 HS = 2 (GH + HS) = 2 GS     (vì H n\u1eb1m gi\u1eefa G và S nên GS = GH + HS)<\/p>Hay JK = 2 GS. T\u1eeb \u0111ó tính \u0111\u01b0\u1ee3c GS.<\/p>","answer":"D\u1ef1a vào \u0111\u1ec1 bài ta có hình v\u1ebd:<\/p><svg height=\"85\" width=\"260\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\"> <g> <title><\/title> <rect fill=\"#fff\" height=\"87\" id=\"canvas_background\" width=\"262\" 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> <image height=\"75\" id=\"svg_1\" width=\"252\" x=\"3\" xlink:href=\"data:image\/png;base64,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\" y=\"5.5\"><\/image> <line fill=\"none\" id=\"svg_2\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"59\" x2=\"50\" y1=\"28.5\" y2=\"38.5\"><\/line> <line fill=\"none\" id=\"svg_8\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"135\" x2=\"126\" y1=\"28.5\" y2=\"38.5\"><\/line> <g id=\"svg_9\"> <line fill=\"none\" id=\"svg_6\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"218\" x2=\"230\" y1=\"30.5\" y2=\"38.5\"><\/line> <line fill=\"none\" id=\"svg_7\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"227\" x2=\"221\" y1=\"29.5\" y2=\"39.5\"><\/line> <\/g> <g id=\"svg_12\"> <line fill=\"none\" id=\"svg_10\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"176\" x2=\"188\" y1=\"30.5\" y2=\"38.5\"><\/line> <line fill=\"none\" id=\"svg_11\" stroke=\"#000\" stroke-linecap=\"undefined\" stroke-linejoin=\"undefined\" stroke-width=\"1.5\" x1=\"185\" x2=\"179\" y1=\"29.5\" y2=\"39.5\"><\/line> <\/g> <\/g> <\/svg><\/span><\/p>Vì H n\u1eb1m gi\u1eefa G và S (theo hình v\u1ebd) nên GS = GH + HS<\/strong>.<\/p>M\u1eb7t khác, vì G là trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng JH nên JH = 2 GH<\/strong>; S là trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng HK nên HK = 2 HS<\/strong>.<\/p>Ta có:  JK =    JH  +   HK    (vì H n\u1eb1m gi\u1eefa J và K)<\/p>           JK = 2 GH + 2 HS    (vì JH = 2 GH ; HK = 2 HS)<\/p>           JK = 2 (GH + HS)    <\/p>           JK = 2 GS<\/p>           46 = 2 GS<\/p>Suy ra  GS = 46 : 2 = 23(cm)<\/span><\/p>\u0110áp án \u0111úng là   GS = 23 cm<\/span><\/strong>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2021-09-09 14:11:13","option_type":"txt","len":0},{"id":"7425","post_id":"4686","mon_id":"1158113","chapter_id":"1158164","question":"Ch\u1ecdn phát bi\u1ec3u \u0111úng<\/strong>.<\/p>","options":["A.<\/strong> Góc t\u1ea1o b\u1edfi hai tia \u0111\u1ed1i nhau có s\u1ed1 \u0111o b\u1eb1ng180o<\/sup><\/span>","B.<\/strong> Hai tia trùng nhau thì t\u1ea1o ra góc b\u1eb9t.","C.<\/strong> Góc có s\u1ed1 \u0111o nh\u1ecf h\u01a1n 180o<\/sup><\/span> là góc vuông.","D.<\/strong> Góc có s\u1ed1 \u0111o l\u1edbn h\u01a1n 0o<\/sup><\/span> là góc vuông."],"correct":"1","level":"3","hint":"","answer":"A.<\/strong> Góc t\u1ea1o b\u1edfi hai tia \u0111\u1ed1i nhau có s\u1ed1 \u0111o b\u1eb1ng 180o<\/sup><\/span><\/span> <\/span> .  (\u0111úng <\/span>vì hai tia \u0111\u1ed1i nhau t\u1ea1o ra góc b\u1eb9t)<\/p>B.<\/strong> Hai tia trùng nhau thì t\u1ea1o ra góc b\u1eb9t.                           (sai<\/span> vì hai tia trùng nhau t\u1ea1o ra góc có s\u1ed1 \u0111o b\u1eb1ng0o<\/sup><\/span>   )<\/p>C.<\/strong> Góc có s\u1ed1 \u0111o nh\u1ecf h\u01a1n 180o<\/sup><\/span>  là góc vuông.               (sai <\/span>vì góc vuông là góc có s\u1ed1 \u0111o b\u1eb1ng90o<\/sup><\/span> )<\/p>D.<\/strong> Góc có s\u1ed1 \u0111o l\u1edbn h\u01a1n  0o<\/sup><\/span>  là góc vuông.                   (sai <\/span>vì góc vuông là góc có s\u1ed1 \u0111o b\u1eb1ng90o<\/sup><\/span> )<\/p>\u0110áp án \u0111úng là  A. Góc t\u1ea1o b\u1edfi hai tia \u0111\u1ed1i nhau có s\u1ed1 \u0111o b\u1eb1ng 180o<\/sup><\/span><\/span> <\/span><\/strong><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2021-09-09 14:27:47","option_type":"txt","len":3}]}