打开App
求阴影部分面积，利用等积代换，原来这么简单！
经典几何题19/31
App05:57
App04:54
App04:39
App04:16
App04:30
App09:31
App07:41
App04:46
App10:07
App05:16
App09:23
App04:47
App08:00
App07:05打开App观看
App05:57App04:54App04:39App04:16App04:30App09:31App07:41App04:46App10:07App05:16App09:23App04:47App08:00App07:05
