Question

如图,AC⊥的DE,垂足为O,∠A=27°,∠D=20°,求∠B与∠ACB的度数

Answer 1

因BC垂直于ED
所∠COD=90
所∠OCD=180-∠COD-∠D=180-90-20=70
所∠ACB=180-∠OCD=110
所∠B=180-∠A-∠ACB=180-27-110=43

追问

是AC⊥DE

追答

sorry,看错了
AC⊥DE
∠AOE=90

则角OEA=180-∠AOE-∠A=63

则角BED=180-角OEA=117
所∠B=180-角BED-角D=43°

所角ACB=180-43-27=110°

不过答案还是一样的

Answer 2

∠AEO=180°-∠A-∠EOA
=63°
∠BED=180°-63°
=117°
∠B=180°-∠D-∠BED
=43°
∠ACB=180-∠B-∠A
=110°

Answer 3

ac⊥de
∠aoe=90
则角oea=180-∠aoe-∠a=63
则角bed=180-角oea=117
所∠b=180-角bed-角d=43°
所角acb=180-43-27=110°