# Find unknown angles in triangles

In this lesson, we will represent the angles in a triangle pictorially and algebraically before learning how to calculate missing angles.

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 shape is being described below?

1/5

Q2.Select the correct description of a trapezium.

2/5

3/5

Q4.What is the value of the missing angle?

4/5

Q5.If a parallelogram has a perimeter of 6cm, what are the lengths of the sides?

5/5

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 shape is being described below?

1/5

Q2.Select the correct description of a trapezium.

2/5

3/5

Q4.What is the value of the missing angle?

4/5

Q5.If a parallelogram has a perimeter of 6cm, what are the lengths of the sides?

5/5

# 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"
• Click "Next" to view the activity

Your video will re-appear on the next page, and will stay paused in the right place.

# 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.

Quiz:

# Find the value of missing angles in triangles - Quiz

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 value of angle a?

1/3

Q2.What is the value of angle a?

2/3

Q3.What is the value of angle y?

3/3

Quiz:

# Find the value of missing angles in triangles - Quiz

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 value of angle a?

1/3

Q2.What is the value of angle a?

2/3

Q3.What is the value of angle y?

3/3

# Lesson summary: Find unknown angles in triangles

## Time to move!

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

For 5 mins...

Move around:
Walk

On the spot:
Chair yoga