What is the total of all the interior angles?
Use Points A or B to change the size of the pentagon. What do you notice about the angles as the pentagon changes sizes?
Move Point D from (1,4) to (2,3)
What other angles does moving Point D affect?
What is point D's angle now?
Are the pentagons on a soccer ball regular pentagons?
How did you come to this conclusion?
All the angles are equivalent (108 degrees).
Using the segment tool in the tool bar, how many triangles can you make in the pentagon?
Use the "slide me" tool, and slide it all the way to the right. What do you notice?
- It makes three triangles [br]- the angles form 3 groups of 180, for each triangle
Check "show exterior angles" and use the "slide me" tool and slide it all the way to the right. What did you notice this time?
All the angles formed a circle, 360 degrees
Does moving the points of the pentagon change the interior or exterior angles?