# Cyclic Quadrilateral: Proof Hint

- Author:
- Tim Brzezinski

In the applet below, feel free to move the

**LARGE POINTS**anywhere you'd like**AT ANY TIME**. Be sure to change the location of the**BLUE POINT**,**PINK POINT**, & other**LARGE POINTS**each time before you re-slide the slider. After interacting with this applet for a few minutes, please answer the questions that follow.## 1.

What is the **SUM** of the measures of the **PINK ARC** and **BLUE ARC** (that you see at the end of the animation)? Why is this?

## 2.

What is the sum of the measures of the **pink angle** and **blue angle**? How do you know this to be true?