Vertical/Opposite Angle Play

Play with vertical angles and parallel lines. Try clicking and hold on point d. Move it around. See what happens to the green and red angles. Can you make the same color angles all equal the same number? We will learn about vertica/opposite angles, alternate interior angles, alternate exterior angles, and other angle relationships this year. If you add a green to a red...what do you get?
Do a red and a green angle that touch always equal 180?