# The statement “Any two opposite sides of a parallelogram are congruent” implies the parallel postulate

Proving the converse is easy enough: you can construct a line between vertices of a parallelogram and then show the resulting triangles are congruent because of adjacent interior angles and ASA congruence of triangles.

However, doesn't the mere existence of a parallelogram imply the parallel postulate? I'm not really sure how to approach this.