# Ratio and proportion in geometry I

In this lesson, we will compare the side lengths of triangles, one of which is an enlargement of the other, and calculate the ratios of the lengths of corresponding sides.

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.Fill in the gap: If two quantities are in the same ratio then there are _______ relationships I can use to find a missing value.

1/5

Q2.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

2/5

Q3.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

3/5

Q4.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

4/5

Q5.Yellow and red counters are in the ratio 2 : 3. What fraction of the counters are yellow?

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.Fill in the gap: If two quantities are in the same ratio then there are _______ relationships I can use to find a missing value.

1/5

Q2.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

2/5

Q3.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

3/5

Q4.Lots of the same groups of yellow and red counters are put in a bag. Fill in the missing value in the ratio table.

4/5

Q5.Yellow and red counters are in the ratio 2 : 3. What fraction of the counters are yellow?

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:

# Ratio and proportion in geometry (part 1)

Show what you've learned by taking this quiz.

Q1.State the ratio between the side lengths AB and BC.

1/5

Q2.State the constant of proportionality between triangle ABC and triangle DEF.

2/5

Q3.Find the length of side DE.

3/5

Q4.Find the length DE.

4/5

Q5.Find the length DE.

5/5

Quiz:

# Ratio and proportion in geometry (part 1)

Show what you've learned by taking this quiz.

Q1.State the ratio between the side lengths AB and BC.

1/5

Q2.State the constant of proportionality between triangle ABC and triangle DEF.

2/5

Q3.Find the length of side DE.

3/5

Q4.Find the length DE.

4/5

Q5.Find the length DE.

5/5

# Lesson summary: Ratio and proportion in geometry I

## 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:
Dance