# Classifying triangles

In this lesson, we learn how to describe the properties of scalene, isosceles and equilateral triangles. We will also learn how to identify and classify triangles inscribed in circles.

#### 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.Decide if the statements are always true, sometimes or never true: All quadrilaterals have 4 lines of symmetry.

1/6

Q2.Decide if the statements are always true, sometimes or never true: The number of lines of symmetry a polygon has is more than its number of sides.

2/6

Q3.Decide if the statements are always true, sometimes or never true: A regular polygon has as many lines of symmetry as it does sides.

3/6

Q4.Decide if the statements are always true, sometimes or never true: The number of lines of symmetry a polygon has is the same as its order of rotational symmetry.

4/6

Q5.How many lines of symmetry does a parallelogram have?

5/6

Q6.How many lines of symmetry does the shape below have?

6/6

#### 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.Decide if the statements are always true, sometimes or never true: All quadrilaterals have 4 lines of symmetry.

1/6

Q2.Decide if the statements are always true, sometimes or never true: The number of lines of symmetry a polygon has is more than its number of sides.

2/6

Q3.Decide if the statements are always true, sometimes or never true: A regular polygon has as many lines of symmetry as it does sides.

3/6

Q4.Decide if the statements are always true, sometimes or never true: The number of lines of symmetry a polygon has is the same as its order of rotational symmetry.

4/6

Q5.How many lines of symmetry does a parallelogram have?

5/6

Q6.How many lines of symmetry does the shape below have?

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.

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

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

# Classifying 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 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

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

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

# Classifying 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 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

# Lesson summary: Classifying triangles

## Time to move!

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

For 5 mins...

Move around:
Climb stairs

On the spot:
Chair yoga