# Find missing angles when two or more polygons are joined

In this lesson, we will apply regular polygon knowledge to find missing angles when two or more polygons are joined together.

#### 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.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

#### 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.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

# Video

Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:

• Click "Close Video"
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# Worksheet

These slides will take you through some tasks for the lesson. If you need to re-play the video, click the ‘Resume Video’ icon. If you are asked to add answers to the slides, first download or print out the worksheet. Once you have finished all the tasks, click ‘Next’ below.

#### Unit quizzes are being retired in August 2023

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

# Find Missing Angles when two or more Polygons are Joined

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

Q1.The diagram shows two hexagons joined. Calculate the size of the angle marked b.

1/4

Q2.A regular pentagon and a regular hexagon are joined. Calculate the size of angle a.

2/4

Q3.An octagon and a nonagon are joined. Calculate the size of the angle labelled g.

3/4

Q4.Calculate the size of the angle marked.

4/4

#### Unit quizzes are being retired in August 2023

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

# Find Missing Angles when two or more Polygons are Joined

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

Q1.The diagram shows two hexagons joined. Calculate the size of the angle marked b.

1/4

Q2.A regular pentagon and a regular hexagon are joined. Calculate the size of angle a.

2/4

Q3.An octagon and a nonagon are joined. Calculate the size of the angle labelled g.

3/4

Q4.Calculate the size of the angle marked.

4/4

# Lesson summary: Find missing angles when two or more polygons are joined

## Time to move!

Did you know that exercise helps your concentration and ability to learn?

For 5 mins...

Move around:
Jog

On the spot:
Chair yoga