In which diagram are angles 1 and 2 vertical angles? 2 lines intersect and form 4 angles. labeled clockwise from the top: blank, 2, blank, 1. 3 lines extend from a point and form 2 angles, labeled 1 and 2. both angles add up to 90 degrees. a horizontal line has 2 lines extending from a midpoint forming 3 angles. labeled from left to right: 1, 2, 3. a horizontal line intersect with another line forming 4 angles. labeled clockwise from top-left: 1, 2, blank, blank.