Question

如下页图,OC是∠AOD的平分线,OE是∠BOD的平分线,若∠AOB=130,∠COD=20,则∠COE和∠BOE的度数

Answer 1

∵OC是∠AOD的平分线,∠COD=20°

∴∠aoc=∠cod=20°

即∠aod=∠aoc+∠cod=20°+20°=40°

∵∠AOB=130°

∴∠dob=∠aob-∠aod=130°-40°=90°

∵OE是∠BOD的平分线

∴∠COE=∠BOE=90°/2=45°