Investigating Mathematics with GeoGebra

Henrico County Public Schools

What is the sum of the exterior angles of a polygon?

READ the instructions on the right and INTERACT with the GeoGebra applet below.
Click on the reset icon icon to reset the diagram.

Sorry, the GeoGebra Applet could not be started. Please install Java 1.4 (or later) to use this page.

Investigation Steps

 Step 1 Close 
  1. Move points A, B, C and/or D on the left to change the quadrilateral.

  2. Next, Move the green point on the slider.

  3. What do you notice?

  4. What relationships exist?
 Step 2 Close 
  1. What do you think is the sum of the exterior angles of a polygon?

  2. Is this sum always true for any polygon?

  3. Can you explain your reasoning?

 More Hands-On Activities Close 
  1. Explore Exterior Angles 2
  2. Explore Exterior Angles 3
  3. Explore Exterior Angles 4