Question

如图所示,AB,CD相交于O点,∠AOE=90°.若∠AOC:∠COE=1:2,求∠AOD?

Answer 1

∠AOC:∠COE=1:2,∠AOE=90°

∠AOC=90°*(1/3)=30°

∠AOD=180°-∠AOC=180°-30°=150°