Year 9

Finding missing sides using sine and cosine for any angle

Year 9

Finding missing sides using sine and cosine for any angle

Lesson details

Key learning points

  1. In this lesson, we will learn how to find missing sides using sine and cosine for any angle in a triangle.

Licence

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

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7 Questions

Q1.
Complete the statement: In a right angled triangle that has an interior angle of 30 degrees, opposite/ hypotenuse = .................
0.2
Correct answer: 0.5
0.87
Q2.
Complete the statement: In a right angled triangle that has an interior angle of 60 degrees, opposite/ hypotenuse = .................
0.2
0.5
Correct answer: 0.87
Q3.
Complete the statement: In a right angled triangle that has an interior angle of 60 degrees, adjacent/ hypotenuse = .................
0.2
Correct answer: 0.5
0.87
Q4.
Complete the statement: In a right angled triangle that has an interior angle of 30 degrees, adjacent/ hypotenuse = .................
0.2
0.5
Correct answer: 0.87
Q5.
What is the length of side a?
An image in a quiz
Correct answer: 1.5 cm
3.4 cm
6 cm
Q6.
What is the length of side b?
An image in a quiz
10 cm
Correct answer: 14 cm
3.5 cm
Q7.
What is the size of angle a?
An image in a quiz
Correct answer: 30 degrees
45 degrees
60 degrees

7 Questions

Q1.
What is the length of side marked q ?
An image in a quiz
10 cm
Correct answer: 2.5 cm
5 cm
Q2.
What is the length of the side marked r ?
An image in a quiz
15 cm
22 cm
Correct answer: 5.5 cm
Q3.
What is the correct step for calculating the length of side b?
An image in a quiz
Correct answer: Option 1
Option 2
Option 3
Q4.
What is the length of of b correct to 1 decimal place?
An image in a quiz
0.86 cm
10 cm
Correct answer: 10.6 cm
Q5.
What is the correct step for calculating the length of side a?
An image in a quiz
Option 1
Option 2
Correct answer: Option 3
Q6.
What is the length of a, correct to 1 decimal place?
An image in a quiz
0.5 cm
23 cm
Correct answer: 23.0 cm
39.2 cm
Q7.
Which ratio would you use to find the length of the missing side in the triangle below?
An image in a quiz
Correct answer: cosine
pythagoras
sine