# Central Angle to Inscribed Angle

- Author:
- Lauren Ryba

- Topic:
- Circle

This is an investigation to determine the relationship between a central angle and an inscribed angle.
The points on the circle and the radius are dynamic and can be moved.

1. Move the points B and C, noting how it changes the two angle values. Create a table of 5 sets of data listing the arc measure, angle BAC and angle BDC
2. Move point D. How does this change the inscribed angle measure?
3. Does changing the radius change the angle measures?
4. What is the relationship between the central angle (BAC) and the arc measure?
5. What is the relationship between the inscribed angle (BDC) and the arc measure? Is this the same relationship between the inscribed angle and central angle?
6. Test your hypothesis by unchecking the boxes, creating a new arc measure and finding the angle measures. Then check the box to check your answer.