小题1:解:(1)成立.·············································· (2分) 如图,把绕点顺时针,得到, 则可证得三点共线(图形画正确)···· (3分) 证明过程中, 证得:··························· (4分) 证得:······················· (5分)
············································································ (6分) 小题2:(2) (8分) |