angle 3 and angle 4 are equal because the diagonals/2 are equal. Angle 4 equals angle 1 due to opposite interior angles thereom. 90 degrees minus 37=53 degrees which is angle 2. Since angle 2 is equal to the angle GKH, 53+53=106 and 180-106=74 degrees, and due to vertical angles, angle 7 is 74 degrees.
