When GF and CD are both perpendicular to AB that must mean that GF and CD are parallel to each other and make 90 degree angles at every angle. When CD is not perpendicular to AB, then AB becomes a transversal line in which the angles that are made with AB from both GF and CD can be vertical, supplementary, corresponding, and alternate interior angles. This is my answer but I need to draw the picture how I got the answer can you help me draw it