The Sum of Outer Angles of a Polygon

About the applet

What is the sum of the angles?


  1. Click some points to make a polygon.
  2. Press "Ok" button to close the polygon.
  3. Press "Scale down" button.
  4. What do you find?

The idea was presented by a participant
at theme group T2
(Computer and teaching of math)
on July, 29 1988
(Sixth International Congress on Mathematical Education)
Budapest, Hungary