Question

If a pair of alternate angles formed by a transversal of two lines is congruent then the two lines are parallel prove that​

Answer 1

Answer:

Euclid's Proposition 27 states that if a transversal intersects two lines so that alternate interior angles are congruent, then the lines are parallel. Euclid proves this by contradiction: If the lines are not parallel then they must intersect and a triangle is formed.