# Internal angles in a quadrilateral

In this lesson, we will be able to use triangles to deduce the sum of the interior angles in a quadrilateral. We will also be able to find unknown angles in quadrilaterals.

# 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

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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.

# Lesson summary: Internal angles in a quadrilateral

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## 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