Investigating the sum of interior angles in polygons
See below to download some worksheet resources that lead an investigation into the sum of interior angles in polygons. They are deliberately aimed at higher ability pupils who have the initiative to access the posed questions. If you were to run this investigation with a lower ability group you may like to use the polygon worksheets but to get them to draw their own results table. That way you can later verbally introduce the questions rather than relying on their literacy skills on a wordy worksheet.
I have found a nice plenary to this lesson is to show them how you can split an n-sided polygon up into n – 2 triangles and therefore calculate the sum of the interior angles as 180(n – 2) degrees.