Finding the sum of interior angles in a polygon

In this lesson, we will calculate the sum of interior angles in polygons, and apply this to find missing angles.

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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 exterior angles of any polygon?

1/5

Q2.Calculate the size of angle a.

2/5

Q3.Calculate the size of angle b.

3/5

Q4.What is the size of each exterior angle of a regular 15 sided polygon?

4/5

Q5.A regular polygon has an exterior angle of 30º. How many sides does it have?

5/5

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.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
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 exterior angles of any polygon?

1/5

Q2.Calculate the size of angle a.

2/5

Q3.Calculate the size of angle b.

3/5

Q4.What is the size of each exterior angle of a regular 15 sided polygon?

4/5

Q5.A regular polygon has an exterior angle of 30º. How many sides does it have?

5/5

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.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

Finding 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.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.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

Finding 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.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

Lesson summary: Finding the sum of interior angles in a polygon

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