Question

如图，OA⊥OB，OC⊥OD，O是垂足，∠BOC=55°，那么∠AOD=______

如图，OA⊥OB，OC⊥OD，O是垂足，∠BOC=55°，那么∠AOD=______．

Answer 1

∵OA⊥OB，OC⊥OD，
∴∠BOA=∠DOC=90°．
∴∠AOD=∠BOD+∠AOB-∠BOC=90°+90°-55°=135°．
故答案是：135°．