Question

The diagram shows a parallelogram ABCD and an equilateral triangle BDE.

CDE is a straight line.

(a) Work out angle BDE
Give a reason for your answer.

(b) Work out angle CDB
Give a reason for your answer.

Answer 1

a) ∠BDE is 60° because ΔBDE is an equilateral triangle with all three angles = 60°.

b) ∠CDB = 120° because 180° - 60° = 120°

Explanation: