Geogebra - What External angle does this polygon have?

In this activity we will investigate the relationship between a polygon and its external angles.

  1. Load this Geogebra file

You should see a triangle.
  1.  Now move the slider marked "vertices"

You should see the the number of external angles change.

  1. Use this spreadsheet to record the external angles of the polygon!
  

 

 
Questions
  1. What is the external angle of an equilateral triangle?
  2. What is the internal angle of an equilateral triangle?  How did you work the answer?
  3. Does your spreadsheet data file reveal a relationship between the number of vertices and the total internal angle of that polygon?
Activities
  1. Change the polygon  shape by moving the vertices slider.  Keep changing the number of vertices until you have filled your spreadsheet data table.
  2. Save a copy of your spreadsheet in your "Maths is Amazing" folder.