Key learning points

1. The sum of the squares of the two shorter sides equals the square of the longest side.
2. The longest side is always opposite the right angle.
3. A calculator can perform these calculations efficiently.
4. Priority of operations makes the order clear.

Common misconception

Keywords

• Pythagoras’ theorem - Pythagoras’ theorem shows that the sum of the squares of the two shorter sides of a right-angled triangle is equal to the square of its longest side (the hypotenuse).

• Hypotenuse - A hypotenuse is the side of the right-angle triangle which is opposite the right-angle.

• Right-angled triangle - A right-angled triangle has exactly one 90° interior angle.