Examine the diagram. Lines b and a intersect lines c and d to form 16 angles. At the intersection of lines b and c, clockwise from top left, the angles are 1, 2, 4, 3. At a and c, clockwise from top left, the angles are 5, 6, 8, 7. At b and d, clockwise from top left, the angles are 13, 14, 16, 15. At a and d, clockwise from top left, the angles are 9, 10, 12, 11. Name two corresponding angles to ∠1. ∠6 and ∠15 ∠5 and ∠6 ∠13 and ∠15 ∠5 and ∠13