A trapezoid with legs MN = FD is an isosceles trapezoid. An isosceles trapezoid has diagonals that are congruent, therefore: MF = ND. A quadrilateral with diagonals congruent and perpendicular is a square. In a square, the height coincides with the side. The area of a square is given by A = s² Therefore, the area of MNFD is h²
