题目内容
直角三角形的两锐角的角平分线的夹角中锐角等于( )
A.30° | B.36.5° | C.45° | D.60° |
如图所示
△ACB为Rt△,AD,BE,分别是∠CAB和∠ABC的角平分线,AD,BE相交于一点F.
∵∠ACB=90°,
∴∠CAB+∠ABC=90°
∵AD,BE,分别是∠CAB和∠ABC的角平分线,
∴∠FAB+∠FBA=
∠CAB+
∠ABC=45°.
故选C.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140825/201408252139080303543.png)
△ACB为Rt△,AD,BE,分别是∠CAB和∠ABC的角平分线,AD,BE相交于一点F.
∵∠ACB=90°,
∴∠CAB+∠ABC=90°
∵AD,BE,分别是∠CAB和∠ABC的角平分线,
∴∠FAB+∠FBA=
1 |
2 |
1 |
2 |
故选C.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140825/201408252139080303543.png)
![](http://thumb.zyjl.cn/images/loading.gif)
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