Google Classroom
GeoGebraGeoGebra Classroom

How Many Diagonals?

  1. Pause the animation at any point (by clicking the pause button in the bottom left corner).
  2. Slide the black dot to set the number of sides of the shape you want to investigate.
  3. Use the check boxes to show/hide all diagonals from a specific vertex.
  4. Do you see the "triangle number pattern"? Try finding some way of multiplying the number of sides by something to get twice the number of diagonals.