10-4 Angles of Polygons pt.1

10-4 Angle sums of polygons

Learning Intent:  I am learning to find angles of regular polygons.

Success Criteria:  I can find the sum of the angles of a regular polygon.

Use the table to develop a formula for the sum of the angles for any regular polygon.

​Find the sum of the interior angles of a decagon (10 sides).

​Find the sum of the interior angles of a octagon.

​Find the sum of the interior angles of a dodecagon (12 sides).

​Find the sum of the interior angles of a 18-gon.

Fill in the bottom row of the table below.

Fill in the bottom row of the table below.

​Find the measure of each angle of a regular hexagon.

​Find the measure of each angle of a regular octagon.

​Find the measure of each angle of a regular nonagon.

​Find the measure of each angle of a regular 20-gon.

Multiple Choice

What can the following formula be used to find?

$$\frac{\left(n-2\right)180}{n}$$

• Sum of exterior angles

• Sum of interior angles

• 1 regular interior angle

• 1 regular exterior angle

Match

Match the following definitions with the correct formula

• Equation used to find what all the sum of all the angles of a specific polygon are

• Equation used to find one interior angle of a specific polygon

• Equation used to find one exterior angle of a specific polygon

• $$180\left(n-2\right)$$

• $$\frac{180\left(n-2\right)}{n}$$

• $$\frac{360}{n}$$

Math Response

Calculate the sum of the angle measures in a polygon with 25 sides.

Type answer here

Correct Answer: 4140

Deg^°

Rad

Math Response

What is the SUM of the angle measures in a nonagon (9 sides)?

Type answer here

Correct Answer: 1260

Deg^°

Rad

Math Response

For a regular NONAGON, find the measure of one interior angle. _____ $$\degree$$  

Type answer here

Correct Answer: 140

Deg^°

Rad

Math Response

For a regular 15-gon, find the measure of one interior angle. ___ $$\degree$$  

Type answer here

Correct Answer: 156

Deg^°

Rad

Math Response

What is the sum of the measures of the interior angles of a 27-gon in degrees?

Type answer here

Correct Answer: 4500

Deg^°

Rad

Math Response

What is the measure of EACH interior angle of a regular 20-gon in degrees?

Type answer here

Correct Answer: 162

Deg^°

Rad

Math Response

Find the measure of each angle indicated. 

Type answer here

Correct Answer: 66

Deg^°

Rad