- Lớp học
- Kiểm Tra
- Thi đấu
- Ôn thi TN THPT
- Ôn thi tốt nghiệp THPT môn Toán - Lớp 12
- Ôn thi tốt nghiệp THPT môn Ngữ văn - Lớp 12
- Ôn thi tốt nghiệp THPT môn Vật lý- Lớp 12
- Ôn thi tốt nghiệp THPT môn Hoá học - Lớp 12
- Ôn thi tốt nghiệp THPT môn Sinh học - Lớp 12
- Ôn thi tốt nghiệp THPT môn Lịch sử - Lớp 12
- Ôn thi tốt nghiệp THPT môn Địa lý - Lớp 12
- Ôn thi Tốt nghiệp THPT môn Giáo dục Kinh tế Pháp luật - Lớp 12
- Giới thiệu
- VinaPhone
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
HomeLớp 10Toán lớp 10 - Sách Kết nối tri thứcBài 6: Các hệ thức lượng trong tam giácBài tập trung bình
{"common":{"save":0,"post_id":"6431","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6429","mon_id":"1158767","chapter_id":"1158829","post_id":"6431","question":"<p>Cho các \u0111i\u1ec3m <span class=\"math-tex\">$A(1;2),B(1;4),C(7;2)$<\/span> Tính s\u1ed1 \u0111o góc <span class=\"math-tex\">$A$<\/span> c\u1ee7a tam giác ABC<\/p>","options":["A. <span class=\"math-tex\">$30^o$<\/span>","B. <span class=\"math-tex\">$60^o$<\/span>","C. <span class=\"math-tex\">$90^o$<\/span>","D. <span class=\"math-tex\">$45^o$<\/span>"],"correct":"3","level":"2","hint":"","answer":"<p><span style=\"color:#27ae60;\"><strong>\u0110áp án \u0111úng là: C. <span class=\"math-tex\">$90^o$<\/span><\/strong><\/span><\/p><p>Ta có: <\/p><p><span class=\"math-tex\">$\\overrightarrow{AB}=(1-1;4-2)=(0;2)$<\/span><\/p><p><span class=\"math-tex\">$\\overrightarrow{AC}=(7-1;2-2)=(6;0)$<\/span><\/p><p><span class=\"math-tex\">$\\overrightarrow{BC}=(7-1;2-4)=(6;-2)$<\/span><\/p><p>\u0110\u1ed9 dài các c\u1ea1nh c\u1ee7a tam giác là:<\/p><p><span class=\"math-tex\">$AB=\\sqrt{0^2+2^2}=2;AC=\\sqrt{0^2+6^2}=\\sqrt{36}=6$<\/span><\/p><p><span class=\"math-tex\">$BC=\\sqrt{6^2+(-2)^2}=2\\sqrt{10}$<\/span><\/p><p>Xét \u0111\u1ed9 dài các c\u1ea1nh, ta th\u1ea5y <span class=\"math-tex\">$AB^2+AC^2=BC^2$<\/span> nên tam giác ABC là tam giác vuông t\u1ea1i A.<\/p>","type":"choose","extra_type":"classic","user_id":"147","test":"0","date":"2023-03-06 00:54:07","option_type":"math","len":0},{"id":"6430","mon_id":"1158767","chapter_id":"1158829","post_id":"6431","question":"<p>Cho tam giác <span class=\"math-tex\">$ABC$<\/span> , <span class=\"math-tex\">$m_a$<\/span>\u200b là \u0111\u1ed9 dài \u0111\u01b0\u1eddng trung tuy\u1ebfn k\u1ebb t\u1eeb \u0111\u1ec9nh A xu\u1ed1ng c\u1ea1nh BC trong tam giác ABC. <\/p><p>Ch\u1ecdn công th\u1ee9c \u0111úng:<\/p>","options":["A. <span class=\"math-tex\">$m_a^2=\\frac{b^2+c^2}{2}+\\frac{a^2}{4}$<\/span>","B. <span class=\"math-tex\">$m_a^2=\\frac{a^2+c^2}{2}-\\frac{b^2}{4}$<\/span>","C. <span class=\"math-tex\">$m_a^2=\\frac{a^2+b^2}{2}-\\frac{c^2}{4}$<\/span>","D. <span class=\"math-tex\">$m_a^2=\\frac{2c^2+2b^2-a^2}{4}$<\/span> "],"correct":"4","level":"2","hint":"<p>Áp d\u1ee5ng h\u1ec7 qu\u1ea3 c\u1ee7a \u0111\u1ecbnh lí Côsin trong tam giác ta có:<\/p><p><span class=\"math-tex\">$m_a^2=\\frac{2c^2+2b^2-a^2}{4}$<\/span><\/p>","answer":"<p><span style=\"color:#27ae60;\"><\/span>\u0110áp án :<span style=\"color:#27ae60;\"><strong> <\/strong><strong>D. <span class=\"math-tex\">$m_a^2=\\frac{2c^2+2b^2-a^2}{4}$<\/span><\/strong><\/span><\/p><p>Áp d\u1ee5ng h\u1ec7 qu\u1ea3 c\u1ee7a \u0111\u1ecbnh lí Côsin trong tam giác.<\/p>","type":"choose","extra_type":"classic","user_id":"147","test":"0","date":"2023-03-06 01:01:50","option_type":"math","len":0},{"id":"6431","mon_id":"1158767","chapter_id":"1158829","post_id":"6431","question":"<p>Tam giác <span class=\"math-tex\">$ABC$<\/span> có <span class=\"math-tex\">$AB=9cm,BC=15cm,AC=13cm$<\/span>. Khi \u0111ó \u0111\u01b0\u1eddng trung tuy\u1ebfn <span class=\"math-tex\">$AM$<\/span> c\u1ee7a tam giác có \u0111\u1ed9 dài là<\/p>","options":["A. <span class=\"math-tex\">${\\sqrt{267}\\over2}cm$<\/span> .","B. <span class=\"math-tex\">${\\sqrt{267}\\over4}cm$<\/span> .","C. <span class=\"math-tex\">${\\sqrt{267}\\over6}cm$<\/span> .","D. <span class=\"math-tex\">${\\sqrt{267}\\over8}cm$<\/span> ."],"correct":"1","level":"2","hint":"<p><span class=\"svgedit\"><svg height=\"217\" width=\"319\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\"> <g><title><\/title><rect fill=\"#fff\" height=\"219\" id=\"canvas_background\" width=\"321\" 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=\"217\" id=\"svg_1\" width=\"319\" x=\"0\" xlink:href=\"data:image\/png;base64,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\" y=\"0\"><\/image> <\/g> <\/svg><\/span><\/p><p>Áp d\u1ee5ng h\u1ec7 qu\u1ea3 c\u1ee7a \u0111\u1ecbnh lí côsin ta có: <\/p><p><span class=\"math-tex\">$AM^2=\\frac{2.9^2+2.13^2-15^2}{4}=\\frac{267}{4}\\Rightarrow AM=$<\/span><span class=\"math-tex\">${\\sqrt{267}\\over2}$<\/span><\/p>","answer":"<p><span style=\"color:#27ae60;\"><strong>\u0110áp án: A<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"147","test":"0","date":"2023-03-06 01:11:11","option_type":"math","len":0}]}