# Substitute the exact values to find a missing length

In this lesson, we will find a missing length of a right angled triangle using prior knowledge of exact trigonometry ratios for 0°, 30°,45°,60° and 90°

#### 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.Which angles of the trigonometry ratios will this triangle help you to find?

1/3

Q2.Which angles of the trigonometry ratios will this triangle help you to find?

2/3

Q3.Find the missing angle in the triangle below.

3/3

#### 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.Which angles of the trigonometry ratios will this triangle help you to find?

1/3

Q2.Which angles of the trigonometry ratios will this triangle help you to find?

2/3

Q3.Find the missing angle in the triangle below.

3/3

# 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:

# Substitute the exact values to find a missing length

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

Q1.Find the length labelled x without a calculator.

1/3

Q2.Find the length labelled x without a calculator.

2/3

Q3.Find the missing length labelled x without using a calculator.

3/3

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

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

# Substitute the exact values to find a missing length

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

Q1.Find the length labelled x without a calculator.

1/3

Q2.Find the length labelled x without a calculator.

2/3

Q3.Find the missing length labelled x without using a calculator.

3/3

# Lesson summary: Substitute the exact values to find a missing length

## Time to move!

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

For 5 mins...

Move around:
Jog

On the spot:
Dance