| If one side of a triangle is 2 times of another side and it has the largest possible area, then the ratio of its three sides is |
A. |
| (英汉小词典:possible 可能的;area面积;ratio比率、比值) |
| 下列各说法中:① 圆的每一条直径都是它的对称轴; ② 长度相等的两条弧是等弧 ;③ 相等的弦所对的弧也相等; ④ 同弧所对的圆周角相等; ⑤ 90°的圆周角所对的弦是直径; ⑥ 任何一个三角形都有唯一的外接圆;其中正确的有 |
A.3个 B.4个 C.5个 D.6个 |