Key learning points

1. Any line segment can be turned into a right-angled triangle by adding two lines which meet at 90°
2. Calculating the horizontal distance gives the length of one side
3. Calculating the vertical distance gives the length of the other side
4. These two shorter sides lengths can be used to calculate the length of the line segment
5. This can be done using Pythagoras' theorem

Common misconception

Keywords

• Hypotenuse - The hypotenuse is the side of a right-angled triangle which is opposite the right angle.

• Pythagoras' theorem - Pythagoras’ theorem states that the sum of the squares of the two shorter sides of a right-angled triangle is equal to the square of the hypotenuse.