This document discusses properties of polygons. It defines a polygon as any closed plane figure with straight sides and a regular polygon as one where all interior angles and sides are equal. It provides a formula to calculate the sum of interior angles of a polygon based on the number of its sides, where the sum equals (n-2) x 180, with an example of calculating the sum for an octagon. The document concludes with an assignment to complete exercise questions 1 to 18.

1. Lesson 36
Polygon Properties
 A polygon is any closed plane figure having
straight sides.
 A regular polygon is a polygon that has all equal
interior angles and all sides are equal.
# of sides of interior angles
3 1800
4
5
6
7
 By using this pattern, if n is the number of
sides, then the sum of the interior angles is
= (n – 2) x 1800
 An octagon has 8 sides so…
= (8-2)*1800
= 6*1800
= 10800
Assignment: Exercise 36 Q 1 to 18