如图,$Rt△ABC$中,$AD$为斜边上垂线.而$O_1$为$△ABD$内心,$O_2$为$△BCD$内心.求证:$∠AO_2B=∠BO_1C$.

872EABA8-779A-43D5-9303-25F9FBEC0D94.png

DFR:4.5

SCR:40