In the diagram above, AB//CD, the bisector of ∠BAC and ∠ACD meet at E. Find…

Explanation

Ae is a bisector of BAC => EAC = 45^o
CE is the bisector of ACD => ACE = 45^o
AEC = 180^o - [EAC + ACE]
    = 180^o - (45^o + 45^o) = 180^o - 90^o = 90^o