Heptagon
7 sided polygon.

A heptagon is a polygon with seven angles and  seven sides. A regular heptagon has seven equal sides and seven equal angles

Using daily life

Octagon

8 sided polygon.

An octagon is a polygon with eight sides.  The most common octagon is the stop sign

Using daily life

Common features

Sum of all angle measures in an n - gon: ( n – 2) • 180º Angle Measures in a Polygon In the activity, you used triangles to find the sum of the angle measures in polygons. In a regular polygon, the measure of one angle is the sum of the angle measures divided by the number of sides. n = number of sides of the polygon  Polygons and Angles  . Measure of one angle in a regular n -gon: ( n – 2) • 180º n

You can watch the video for polygons.

RESOURCES: YouTube, Google, Slide Share