I will prove that triangles ______, ______, ______, ______ and ______ are congruent using the Side-Angle-Side Triangle Congruence Theorem. The same argument works for all the triangle pairs. 2) Sides ______ and ______ are congruent because ______ bisects the diagonals. 3) Sides ______ and ______ are congruent because ______ bisects the diagonals. 4) Angles ______, ______, ______ and ______ are congruent because ______ is perpendicular to ______, so their intersection forms four right angles. Right angles are congruent. Therefore, all four triangles are congruent by the Side-Angle-Side Triangle Congruence Theorem. 5) Sides ______, ______, ______, and ______ are all corresponding parts of congruent triangles, so they are congruent. Therefore _______ is equilateral.