Pythagoras’ Theorem

This lesson covers:

  1. How to find a missing side length in a right-angled triangle using Pythagoras' Theorem
  2. Pythagoras' Theorem: a2 + b2 = c2

True or False? Pythagoras' Theorem can only be used with right-angled triangles.

False

True

0

/

1

When using the Pythagoras equation below, which letter represents the hypotenuse?


a2 + b2 = c2

b

c

a

0

/

1

Which side of the triangle below is the hypotenuse? 

Right angle triangle with sides labelled 25 cm, 24 cm, and 7 cm showing the hypotenuse.

24 cm side

7 cm side

25 cm side

0

/

1

Calculate the length of the missing side in the diagram below. Give your answer to 3 significant figures.

Diagram of a right triangle with a 6 cm base, a 4 cm height, and a missing hypotenuse indicated by a question mark.
7.21

cm

cm

0

/

1

Calculate the length of the missing side in the diagram below.

Right-angled triangle with sides 5m and 12m, missing side marked with a question mark.
13

m

m

0

/

1

Calculate the length of the missing side in the diagram below. Give your answer to 3 significant figures.

Right triangle with sides 8 cm and 11 cm, missing side marked with a question mark.
13.6

cm

cm

0

/

1

Calculate the length of the missing side in the diagram below. Give your answer to 3 significant figures.

Right-angled triangle diagram with sides 9 cm and 15 cm, missing side marked with a question mark.
12

cm

cm

0

/

1

Calculate the length of the missing side in the diagram below. Give your answer to 3 significant figures.

Diagram of a right triangle with two sides of 5 cm each and a missing side.
7.07

cm

cm

0

/

1

Calculate the length of the missing side in the diagram below.

Right-angled triangle with sides of 8 cm and 17 cm, and a question mark indicating the missing side length.
15

cm

cm

0

/

1

Calculate the length of the missing side in the diagram below. Give your answer to 3 significant figures.

Diagram of a right-angled triangle with sides labeled 6 mm and 8 mm, and a question mark indicating the missing side.
5.29

mm

mm

0

/

1