From the condition, segment DG is congruent to segment DC. So the triangle DGC is isosceles. The angle GDC of this triangle is 60° + 90° = 150°. Therefore, the two angles DGC and DCG are congruent as the base angles of the isosceles triangle GDC and have measure= 15° each. Then the angle DHG is the complement of the angle DGH, since these angles are the acute angles in the right angled triangle DHG. Thus the angle DHG is 75°. ANSWER