小结与思考第11题答案
∠AOB = ∠COD = 46°,∠AOD = 124°
小结与思考第12题答案
(1)图略;
(2)图略;
(3)图略;
(4)AD = DB,BE = CE,∠BDE = ∠BAC,
∠BED = ∠BCA,∠ABC = ∠ACB,∠BED = ∠ABC;
(5)AE⊥BC;
(6)如∠EAC与∠ECA互余,∠DEA与∠BED互余,如∠DEC与∠BCA互补,∠EDA与∠DAC互补
小结与思考第13题答案
∠BOD = ∠AOC,∠AOC = ∠COE,得∠BOD = ∠COE
小结与思考第14题答案
由∠AOC与∠AOD互余,∠AOC与∠BOC互余,得∠AOD = ∠BOC
又∠AOE = ∠COE,所以∠BOE = ∠DOE
所以OE是∠BOD的平分线