Inscribed Quadrilateral

1. Move the vertices of the quadrilateral around and look for a pattern between the opposite angles of the inscribed quadrilateral (angle C and angle E, angle D and angle F). 2. Once you think you know the pattern, uncheck the "Show measure of angle E and angle F" box. 3. Change the measure of angles C and D. 4. Calculate the measure of angle E and the measure of angle F. 5. Then click the box to check your solutions.

The opposite angle of an inscribed quadrilateral are always _______________.