Find the number of sides when given the sum of interior angles

In this lesson, we will find the number of sides of a polygon when given only the sum of interior angles.

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What is the sum of interior angles of a 20-sided shape?

1/4

Q2.What is the sum of interior angles of a 9-sided shape?

2/4

Q3.What is the missing angle, labelled x?

3/4

Q4.What is the size of each interior angle in a regular octagon?

4/4

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What is the sum of interior angles of a 20-sided shape?

1/4

Q2.What is the sum of interior angles of a 9-sided shape?

2/4

Q3.What is the missing angle, labelled x?

3/4

Q4.What is the size of each interior angle in a regular octagon?

4/4

Video

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Worksheet

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This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Find the Number of Sides when given the Sum of Interior Angles

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.The sum of interior angles of a polygon is 720º. How many sides does the polygon have?

1/4

Q2.The sum of interior angles of a polygon is 2880º. How many sides does the polygon have?

2/4

Q3.The sum of interior angles of a regular polygon is 3960º. What is the size of each interior angle of the regular polygon?

3/4

Q4.The sum of interior angles of a regular polygon is 5040º. What is the size of each exterior angle of the regular polygon?

4/4

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Find the Number of Sides when given the Sum of Interior Angles

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.The sum of interior angles of a polygon is 720º. How many sides does the polygon have?

1/4

Q2.The sum of interior angles of a polygon is 2880º. How many sides does the polygon have?

2/4

Q3.The sum of interior angles of a regular polygon is 3960º. What is the size of each interior angle of the regular polygon?

3/4

Q4.The sum of interior angles of a regular polygon is 5040º. What is the size of each exterior angle of the regular polygon?

4/4

Lesson summary: Find the number of sides when given the sum of interior angles

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