Sample lesson

Pythagoras' Theorem 2

Progress:

5

10

4

10

You should use a calculator for this lesson

The notes are hidden when you only need 1 or 2 correct answers to complete the lesson. Also you cannot see the worked solutions  or  have  the  easier  questions. 

Find the length of the side marked 𝑥. Give your answer correct to 3 significant figures.

Find the length of the side marked 𝑥

Is the side marked 𝑥 the longest side or is it one of the two shorter sides?

7cm

𝑥

10cm

𝑥

5cm

𝑥

7cm

𝑥

5cm

10cm

𝑥

𝑥

5cm

𝑥

10cm

𝑥

𝑥

7cm

10cm

𝑥

5cm

𝑥

𝑥

7cm

cm

Longest
Shorter

Correct

This is not correct.
We are finding one of the two shorter sides, so we need to find

the difference between the squares of the two given sides.


𝑥² = 25² − 11²
    = 625 − 121
    = 504
𝑥 = √504
   = 22.4cm  (to 3 s.f.)

This is not correct.
We are finding the hypotenuse, so we need to

add the squares of the two given sides.


𝑥² = 10² + 6²
    = 100 + 36
    = 136
𝑥 = √136
   = 11.7cm  (to 3 s.f.)

This is not correct.

The side marked 𝑥 is opposite the right angle

(it is the hypotenuse), so it is the longest side.

This is not correct.

The side marked 𝑥 is one of the two sides that have the right angle

between them, so it is one of the two shorter sides.

The side marked 𝑥 is one of the two sides that have the right angle

between them, so it is one of the two shorter sides.

The side marked 𝑥 is opposite the right angle

(it is the hypotenuse), so it is the longest side.