Question

已知:如图,∠AOB=1/2∠BOC,∠COD=∠AOD=3∠AOB，求∠AOB、∠ AOC、∠COD的度数

Answer 1

解：
∵∠AOB＝1/2∠BOC
∴∠BOC＝2∠AOB
∵∠AOB+∠BOC+∠COD+∠AOD＝360
∠COD＝∠AOD＝3∠AOB
∴∠AOB+2∠AOB+3∠AOB+3∠AOB＝360
∴∠AOB＝40
∴∠BOC＝2∠AOB＝80
∠AOC＝∠AOB+∠BOC＝40+80＝120
∠COD＝3∠AOB＝120
答：∠AOB＝40, ∠AOC＝120, ∠COD＝120

Answer 2

∠AOB=1/2∠BOC ∠BOC=2∠AOB
∠COD=∠AOD=3∠AOB
3∠AOB（∠COD）+3∠AOB（∠AOD）+2∠AOB（∠BOC）+∠AOB=360°
（3+3+2+1）∠AOB=360°
9∠AOB=360°
∠AOB=40°
~~~~~~~~~~~~~~~~~~~~~你自己写吧

Answer 3

AOB=40°AOC=120°。COD=120°