Line segments AB and CD intersect at O such that AC || DB. If ∠CAB = 45° and ∠CDB =55°, then ∠BOD =

In a Δ ABC, If ∠A = 60°, ∠B =80° and the bisectors of ∠B and ∠C meet at O, then ∠BOC=

If the bisectors of the acute angles of a right triangle meet at O, then the angle at O between the two bisectors is

The bisectors of exterior angles at B and C of Δ ABC meet at O, if ∠A= x°, then ∠BOC =

In Δ ABC, ∠A=50° and BC is produced to a point D. If the bisectors of ∠ABC and ∠ACD meet at E, then ∠E =