In the given figure, AE and BC are equal and parallel. If the sides AB, CD and DE are equal and ∠BAE = 100°, then ∠BCD is equal to
160°
Solution: Join CE
A
ABCE is a parallelogram (one pair of opposite sides are equal and parallel)
Therefore, AB = CE =CD = DE ….. (i)
CDE is equilateral …… (from (i)
Thus ∠ECD=60∘
∠BCE=∠BAE=100∘ ….. (opposite angles of a parallelogram)
Thus, ∠ACD=∠ACE+∠ECD
=100∘+60∘
=160∘
Hence (D)