Question

In the figure AB is parallel to DC. Find the value of ∠1 and ∠2. Justify your answer

Answer 1

Given AB || DC

AB and CD are parallel lines Taking CE as transversal we have.

∠1 = 30°  ...[∵ alternate interior angles]

Taking DE as transversal

∠2 = 80° ...[∵ alternate interior angles]

∠1 = 30° and ∠2 = 80°

Justification:

CDE is a triangle

∠AEC + ∠CED + ∠DEB = ∠DEC + ∠ECD + ∠CDE

∠1 + 80° = 30° + ∠2

∴ 30° + 80° = 30° + 80°.