Angle measures in polygons are affected by the number of sides the polygon has.

To explore the relationship of sides and angles of a polygon, click on the picture and follow the directions below. This will open in a new webpage.

You can change the number of sides of the polygon by clicking on the gray words “more” or “less” to the right of the polygon. 

Select three sides, a triangle, and then use your notes to record your answers to the following questions.

1. What happens when you click the word “less” over and over?
   
   Interactive popup. Assistance may be required.

   Check Your Answer

   The number of sides will never be less than three.
   
   
   
2. Why do you think the number of sides will not go below 3?
   
   Interactive popup. Assistance may be required.

   Check Your Answer

   A polygon must have at least three sides.  If it had only two sides, they would have to either be intersecting or parallel lines, which do not form a polygon.
   
   
   
3. Now, begin increasing the number of sides of the polygon by clicking the word “more”.  What do you notice about the measure of each angle?
   
   Interactive popup. Assistance may be required.

   Check Your Answer

   The angles increase in size.
   
   
   
4. What do you notice about the sum of the measures of the angles?
   
   Interactive popup. Assistance may be required.

   Check Your Answer

   The sums increase.