# Exterior Angles Investigation

- Author:
- Jennifer Beierman, Tim Brzezinski, Jesse Parete

- Topic:
- Angles

## Objective

Your learning objective is to discover the relationship between the exterior angles of a polygon and develop a way to extend your understanding to all regular polygons.

## TRIANGLE

## 1.

What seems to be true about a triangle's exterior angles? Describe what you see.

## 2.

Suppose the **blue angle measures 130 degrees** and the **pink angle measures 150 degrees**.
**
Predict what the measure of the purple angle be? **

**Note:**For the polygons that follow (quadrilateral, pentagon, hexagon), these applets will work best if the polygon is kept

**CONVEX**. If you don't remember what this term means, click here for a refresher.

## QUADRILATERAL

## 3.

What seems to be true about a quadrilateral's exterior angles? Describe what you see.

## 4.

Suppose the **blue angle measures 110 degrees** and the **pink angle measures 120 degrees **and the **green angle measures 60 degrees**.
**
What will the measure of the purple angle be? **

## PENTAGON

## HEXAGON

## 5.

What can we conclude about a pentagon's 5 exterior angles? What can we conclude about a hexagon's 6 exterior angles? Describe the phenomena you observed.

## Quick Demo. BGM: Andy Meyers

## What about regular polygons?

Consider the regular pentagon below. Use the diagram to look at this relationship.