摘要: 如图, 已知AB=AC, AE=AD, 点D.E分别在AB.AC上, 求证: ∠B=∠C.
网址:http://m.1010jiajiao.com/timu_id_2079180[举报]
| AB |
| a |
| AC |
| b |
(1)用向量
| a |
| b |
| AE |
| BE |
(2)作出向量
| BD |
| a |
| b |
| A、30°,120° | B、35°,140° | C、45°,135° | D、25°,150° |
网址:http://m.1010jiajiao.com/timu_id_2079180[举报]
| AB |
| a |
| AC |
| b |
| a |
| b |
| AE |
| BE |
| BD |
| a |
| b |
| A、30°,120° | B、35°,140° | C、45°,135° | D、25°,150° |