题目内容
(满分12分)如图,已知是⊙O的直径,是弦,过点作OD⊥AC于,连结.
1.(1)求证:;
2.(2)若,求∠的度数.
1.证法一:是⊙O的直径
······················· (2分)
又
······················· (4分)
······················ (6分)
证法二:是⊙O的直径
················ (2分)
即
又 ······················ (3分)
··················· (4分)
···················· (5分)
2.(2)(6分)
解:是⊙O的直径,
······················· (3分)
解析:略
练习册系列答案
相关题目