题目内容
(本小题满分12分)
已知在△
中,角
所对的边分别为
,向量
(1)若
,且
平行,求角
的大小
(2)若
,求
的面积
已知在△




(1)若



(2)若



解(1)当
时,
,因为
平行,所以
所以
,因为
是三角形的内角,所以
6分
(2)
,所以
,
1分
由
,
得
3分
又因为
4分
所以
的面积
=
6分




所以




(2)



由




又因为


所以




略

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