Question

ABCD is a quadrilateral in which AB || DC and AD || BC. Find ∠b, ∠c and ∠d.

Answer 1

∠b + ∠50° = 180° (int. angles on the same side of AB) 

∠b = 180° – 50° = 130° 

Similarly ∠b + ∠c = ∠c + ∠d = ∠d + ∠50 = 180° 

∠130° + ∠c = 180° 

∠c = 180° – 130° = 50° 

Also ∠c + ∠d = 50° +∠d = 180° 

∠d = 180° – 50° = 130°