# IM2.7 T6 Cyclic Quadrilaterals

- Author:
- 00JonLind, Tim Brzezinski

- Topic:
- Quadrilaterals

Any

**quadrilateral that is inscribed inside a circle**is said to be a*In the applet below, a cyclic quadrilateral (with moveable vertices) is shown. Slide the slider slowly and carefully observe what happens. Then, reset the applet. Change the locations of the BIG POINTS and repeat this process. Repeat the previous steps a few more times. Then, answer the questions that follow.***cyclic quadrilateral**.1) Suppose, in the applet above, the red angle measures 76 degrees. What would the measure of the blue angle be?

*inscribed angles*of a circle. Explain why, using your previous work with inscribed angles, the phenomena you've observed above holds true for any cyclic quadrilateral.