Bài 5: Cho ABC vuông tại A (AB >AC), trên tia đối tia AC lấy điểm D sao cho AC=AD a/ Chứng minh: ABC = ABD b/ Từ A kẻ AH  BD (H thuộc BD) và kẻ AK  BC( K thuộc BC).Chứng minh: AHK là tam giác cân c/ Từ D kẻ đường thẳng song song với BC cắt đường thẳng AK tại M. Chứng minh: AHM cân và HM  HK

Các câu hỏi liên quan

help me! Ex 1. Choose the word whose stress pattern is different from that of the others (Tìm 1 từ có trọng âm khác so với 3 từ còn lại) 1, A. artistic B. historic C. dramatic D. scientific 2, A. medical B. national C. chemical D. historycal 3, A. athletic B. dramatic C. scientific D. heroic 4, A. medical B. hospital C. politic D. electric 5, A. chemical B, physical C. environmental D. medical Ex 2. Combine the sentences 11 each pair into a new sentence that slows a cause/ effect relationship. Use the words in brackets. (Viết lại câu sao cho nghĩa không thay đổi, sử dụng từ gợi ý) 1. The food is contaminated. People’s health is poor. (results in) ……………………………………………………………………………………………… 2. The environment is polluted. Birds leave their habitats and plants die. (makes) ……………………………………………………………………………………………… 3. Emma came first because she worked hard. (result) ……………………………………………………………………………………………… 4. Eating too much sugar can result in health problems. (lead) ……………………………………………………………………………………………… 5. Acid rain is dangerous. Trees’ leaves are damaged. (because of) ……………………………………………………………………………………………… 6. Factories release fumes. The air people breathe gets polluted. (due to) ……………………………………………………………………………………………… 7. Many rivers and lakes are poisoned. Factories produce waste and pour it into rivers and lakes. (because) ……………………………………………………………………………………………… 8. Plastic bags are a major source of waste. We should not throw plastic bags everywhere. (so) ………………………………………………………………………………………………… 9. Noise pollution happens. There is a change in animals’ living pattern. (causes) ……………………………………………………………………………………………… 10. Although he took a taxi, he still arrived late for school. (in spite of) ………………………………………………………………………………………………….