M18 | Maths Made Easy


Question: Below is a right-angled triangle. Work out the length of the side marked x. Give your answer to two decimal places.

Answer: To do this we will need to use Pythagoras theorem a^2+b^2=c^2

We then add the numbers we know into the equation. This gives us


Next, we need to rearrange to make x the subject.

x^2=13^2 - 9^2

Next if we then calculate the right-hand side:

x^2=169 - 81


Finally, we square root both sides


Which gives the final answer to be x=9.38 (2d.p.)