Vertical Angles Exploration

Definition: Vertical Angles are opposite pairs of angles made by intersecting lines. When 2 lines intersect, 2 pairs of vertical angles are formed. One pair of vertical angles is shown below. (Click the other checkbox on the right to display the other pair of vertical angles.) Interact with the following applet for a few minutes, then answer the questions that follow.

Based upon your observations, what conclusions can you make about vertical angles?

Suppose the measure of the pink angle was 140 degrees. What would the measure of its vertical angle be?