Pythagoras' Theorem

Pass Check: Pythagoras' Theorem

a^2 + b^2 = c^2 for right-angled triangles only; c is always the hypotenuse.

4 definitions3 to memorise3 common mistakes5 exam questions8-question quiz

Hypotenuse

The longest side of a right-angled triangle, opposite the right angle.

Pythagoras' theorem

In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.

Pythagorean triple

A set of three whole numbers satisfying a^2 + b^2 = c^2, e.g. 3, 4, 5.

3D Pythagoras

Applying the theorem twice (or once in 3D form) to find a diagonal through a cuboid.

Quick check

Mixed quiz

1. A right-angled triangle has shorter sides 9 cm and 12 cm. Find the hypotenuse.

2. A right-angled triangle has shorter sides 7 cm and 24 cm. Find the hypotenuse.

3. A right-angled triangle has hypotenuse 17 cm and one shorter side 8 cm. Find the other shorter side.

4. A right-angled triangle has shorter sides 6 cm and 8 cm. Find the hypotenuse.

5. A right-angled triangle has shorter sides 3 cm and 4 cm. Find the hypotenuse.

6. A right-angled triangle has hypotenuse 13 cm and one shorter side 5 cm. Find the other shorter side.

7. A right-angled triangle has shorter sides 8 cm and 15 cm. Find the hypotenuse.

8. A right-angled triangle has hypotenuse 5 cm and one shorter side 3 cm. Find the other shorter side.