Question

Prove that if the two arms of an angle are perpendicular to the two arms of another ange then the angles are either equal to the supplementry

Answer 1

In this case: BA is parallel to ED and BC is transversal therefore, ∠ABC= ∠1 [corresponding angles] again , FE is parallel to BC and ED is transversal therefore, ∠DEF= ∠1 [alternate interior angles] hence, ∠ABC= ∠DEF