Prove that two quadrilaterals are congruent

Question

If two quadrilaterals $ABCD$ and $PQRS$ have angles $∠A, ∠B, ∠C, ∠D$ equal to angles $∠P, ∠Q, ∠R, ∠S$ respectively, and $AB=PQ$, $CD=RS$, and $AD$ is not parallel to $BC$. Prove that the two quadrilaterals are congruent.