Which is enough information to prove that s is parallel to t? Lines s and t are cut by transversal r to form 8 angles. Clockwise from top left, the angles formed with lines r and s are 1, 2, 3, 4; formed with lines r and t are 5, 6, 7, 8. Angle 1 is congruent to angle 3 Angle 2 is congruent to angle 8 Angle 5 + angle 6 = 180 degrees Angle 1 + angle 4 = 180 degrees