1.∠DOA=∠BOE=∠EOA-∠BOA=125°-90°=35° ∠BOD=∠EOA-∠EOB-∠DOA=125°-35°-35°=55°
2.∠AOE=∠DOA+∠DOB+∠EOB=2∠DOA+∠BOD=4∠BOD ∠DOA=3∠BOD/2 ∠DOA+∠BOD=3∠BOD/2+∠BOD=5∠BOD/2=90° ∠BOD=90°*2/5=36° ∠EOB=∠DOA=3∠BOD/2=3*36°/2=54°
3.当旋转角不超过90度,OB不越出∠AOB时,∠BOD+∠AOE不会变化.因旋转时∠BOD减少的度数同∠AOE增加的度数相等.
当旋转角超过90度,OB越出∠AOB时,∠BOD+∠AOE会变化.因此时∠BOD不是减少而是增加度数了,和∠AOE增加的度数一样多.