Google Classroom
GeoGebraGeoGebra Classroom

Unit 1 - Day 14

Look at the polygons in the application below.

Why do you think these polygons are called regular polygons?

Use what you know about the Polygon Angle Sums to answer the following questions. (Make sure you have the "show angles" box checked)

Why do the angles of the regular triangle (equilateral) have to equal 60°?

Why do the angles of the regular quadrilateral (square) have to equal 90°?

Why do the angles of the regular pentagon have to equal 108°?

Why do the angles of the regular hexagon have to equal 120°?

Determine the measure of each angle in a regular octagon (8 sided polygon). Explain how you found your answer.

Determine the measure of each angle in a regular decagon (10 sided polygon). Explain how you found your answer.

The formula to find the sum of a polygon's angles (S) is given by the following equation: S = (n-2)*180 (where n is the number of sides).

Use this formula to write an equation that will calculate the measure of each angle (A) of a regular polygon with n sides. Your equation should be of the form A = [expression involving n].

Use your equation to determine the measure of each angle of a regular 12-sided polygon.

Use your equation to determine the measure of each angle of a regular 20-sided polygon.

Each angle of a regular polygon measures 156°. Use your equation to determine the number of sides that the polygon has.

Each angle of a regular polygon measures 165°. Use your equation to determine the number of sides that the polygon has.

Enjoy!