# 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.

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.Decide if the following statement is always, sometimes or never true: The diagonals of a quadrilateral intersect.

1/6

Q2.Decide if the following statement is always, sometimes or never true: The diagonals of a rhombus are perpendicular.

2/6

Q3.Decide if the following statement is always, sometimes or never true: The diagonals of a trapezium are perpendicular.

3/6

Q4.Decide if the following statement is always, sometimes or never true: The diagonals of a quadrilateral are the same length

4/6

Q5.Which line (A, B or C) is a diagonal of this shape?

5/6

Q6.The diagonals of a three quadrilaterals are shown, draw and name the shapes.

6/6

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.Decide if the following statement is always, sometimes or never true: The diagonals of a quadrilateral intersect.

1/6

Q2.Decide if the following statement is always, sometimes or never true: The diagonals of a rhombus are perpendicular.

2/6

Q3.Decide if the following statement is always, sometimes or never true: The diagonals of a trapezium are perpendicular.

3/6

Q4.Decide if the following statement is always, sometimes or never true: The diagonals of a quadrilateral are the same length

4/6

Q5.Which line (A, B or C) is a diagonal of this shape?

5/6

Q6.The diagonals of a three quadrilaterals are shown, draw and name the shapes.

6/6

# 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:

# Internal angles in quadrilaterals Quiz

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

Q1.Find the size of each missing angle

1/6

Q2.Calculate the missing angle, labelled x

2/6

Q3.Find the missing angles, x, y and z

3/6

Q4.Find the size of the missing angles

4/6

Q5.Shown below is a rhombus. Calculate each of the missing angle

5/6

Q6.Find the size of each of the missing angle

6/6

Quiz:

# Internal angles in quadrilaterals Quiz

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

Q1.Find the size of each missing angle

1/6

Q2.Calculate the missing angle, labelled x

2/6

Q3.Find the missing angles, x, y and z

3/6

Q4.Find the size of the missing angles

4/6

Q5.Shown below is a rhombus. Calculate each of the missing angle

5/6

Q6.Find the size of each of the missing angle

6/6

# Lesson summary: Internal angles in a quadrilateral

## 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