# Circumcenter - 2019

- Author:
- Rebecca Young

- Topic:
- Geometry

## Follow the steps below to construct the circumcenter.

Use to construct the perpendicular bisector of segments AB, BC and AC.
Use to add a point where the three perpendicular bisectors intersect.
Use to label the point where the perpendicular bisectors intersect.

**The point where all three perpendicular bisectors intersect is called the circumcenter. **
1. Use to move point A, B or C so that the **circumcenter** is outside the triangle. What do you notice about the triangle?

2. Use to move point C so that the **circumcenter** lies on a side of the triangle. What do you notice about the triangle?

## We are now going to learn about the properties of a circumcenter.

Use to draw a segment from A to the

**circumcenter**. Use to measure the length of the segment from A to the**circumcenter**. Repeat the process for vertex B and C Use to draw a circle with center at the**circumcenter**and through point A.## Circumcenter Properties

3. Use to move point A, B or C around. What do you notice about the dashed segment lengths?

## The Circle

4. You constructed the circle to go through point A. When you move the triangle, you should notice that the circle also always goes through B and C. Why is that?

## Application for Circumcenter

5. For which of the following situations, would it make sense to find the **circumcenter**?