Maths

Exit Lesson

Angles in a triangle

In this lesson, we will understand that the interior angles in a triangle sum to 180°. We will also solve problems involving unknown angles in triangles.

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.

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 a triangle with at least two equal sides called?

1/6

Q2.What is a triangle with three equal sides called?

2/6

Q3.Would it be possible to draw a scalene triangle with more than one obtuse angle?

3/6

Q4.The sum of all the angles of a triangle is:

4/6

Q5.Zaki and Connor are looking at the diagram on the right. Who do you agree with? Why?

5/6

Q6.I am thinking of a triangle which have the following properties: no lines of symmetry and has one right angle. Which triangle am I thinking of?

6/6

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.

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 a triangle with at least two equal sides called?

1/6

Q2.What is a triangle with three equal sides called?

2/6

Q3.Would it be possible to draw a scalene triangle with more than one obtuse angle?

3/6

Q4.The sum of all the angles of a triangle is:

4/6

Q5.Zaki and Connor are looking at the diagram on the right. Who do you agree with? Why?

5/6

Q6.I am thinking of a triangle which have the following properties: no lines of symmetry and has one right angle. Which triangle am I thinking of?

6/6

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.

Quiz:

Angles in a Triangle

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

Q1.Grace has measured the three angles in a triangle. Two of her measurements are 48° and 70°. What is the third measurement?

1/6

Q2.Find the size of the missing angle

2/6

Q3.Find the missing angle labelled, x

3/6

Q4.Find the missing angle, labelled x

4/6

Q5.Work out the missing angle, labelled x

5/6

Q6.The ratio of three angles in a triangle are 1:2:3. Work out the size of each angle.

6/6

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.

Quiz:

Angles in a Triangle

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

Q1.Grace has measured the three angles in a triangle. Two of her measurements are 48° and 70°. What is the third measurement?

1/6

Q2.Find the size of the missing angle

2/6

Q3.Find the missing angle labelled, x

3/6

Q4.Find the missing angle, labelled x

4/6

Q5.Work out the missing angle, labelled x

5/6

Q6.The ratio of three angles in a triangle are 1:2:3. Work out the size of each angle.

6/6

Lesson summary: Angles in a triangle

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Classifying 2-D shapes
is:
Comparing quadrilaterals

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