# Center Angle, Inscribed Angle, Circular Segment Angle and Capable Arc

- Author:
- Jorge Cássio

- Topic:
- Angles

## PROPERTY OF THE INSCRIBED ANGLE

## Reflection 1

Move the points A, B or C and compare the angles. What do you notice?

## Proof

## Guidelines for understanding of proof

Change the "steps" selector and note the justification steps. Do you understand? If you have not understood the property of the external angle click here and check. Return the selector to step 0. Move point C down. Observe the justification steps. Do you understand? Return the selector to step 0. Move point C upwards. Observe the justification steps. Do you understand?

## Measure of circular segment angle

## Reflection

Change the position of point C and compare the angles of the circular segment and the center angle. What do you notice?

## Arc capable and inscribed angle

## Reflection 3

What is the angle of the AEB? and the angle ADB? Why?

## Note

The activity was elaborated in Portuguese (Brazil) and translated into English. It is important to improve! jcassio@gmail.com