To calculate the length of a side on a right-angled triangle when you know the sizes of the other two, you need to use Pythagoras' Theorem.

Pythagoras' Theorem says that, in a right angled triangle:

The square of the hypotenuse is equal to the sum of the squares on the other two sides.

We can write this more simply as :

- Question
Use Pythagoras' Theorem to calculate the length of the hypotenuse. Give your answer to 2 decimal places.

Write the equation

Square the lengths you know

Add together

Find the square root

- Question
Calculate the length of side

(Give your answer to 2 decimal places)

Calculate the length of the side marked .

Give your answer to 2 decimal places.

- Write the equation:
- Organise the equation . To find the length of a short side, we can also use the formula
- Square the lengths you know:
- Do the subtraction:
- Find the square root:

- Question
Calculate the length of side a.

Give your answer to 2 decimal places