Question

Which lists all the lines that are parallel to line s?

Lines s, t, u, and v are cut by transversal r. Clockwise from top left, the angles formed by r and s are blank, 89 degrees, blank, blank; formed by r and t are 89 degrees, blank, blank, blank; formed by r and u are 91 degrees, blank, blank, blank; formed by r and v are blank, 89 degrees, blank, blank.
only line v
only line t and line v
only line u and line v
only lines t, u, and v

Answer 1

Only line u and line v.

Reason: s has top-right = 89°, so its top-left = 180 − 89 = 91°. Line u's top-left is 91° (matches s's top-left) and line v's top-right is 89° (matches s's top-right). Corresponding/alternate-equal angle pairs imply the lines are parallel, so u and v are parallel to s; t is not.