# Use inverse functions to find an angle

In this lesson, we will find a missing angle in a given triangle using the inverse trigonometric functions. We will need to interpret which trigonometric ratio to use, and rearrange it.

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.Use your calculator find the value of cos(56) to 3 decimal places.

1/3

Q2.Use your calculator find the value of tan(89) to 3 decimal places.

2/3

Q3.Use your calculator to work out the size of sinѲ = 0.21 . Give your answer to one decimal place.

3/3

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.Use your calculator find the value of cos(56) to 3 decimal places.

1/3

Q2.Use your calculator find the value of tan(89) to 3 decimal places.

2/3

Q3.Use your calculator to work out the size of sinѲ = 0.21 . Give your answer to one decimal place.

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.

Quiz:

# Use inverse functions to find an angle

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

Q1.Which of the trigonometry ratios will be required to find the missing angle in this question?

1/3

2/3

3/3

Quiz:

# Use inverse functions to find an angle

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

Q1.Which of the trigonometry ratios will be required to find the missing angle in this question?

1/3

2/3

3/3

# Lesson summary: Use inverse functions to find an angle

## Time to move!

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For 5 mins...

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