Pythagoras' theorem

What you'll learn

1. 1

   Imagine a right-angled triangle drawn on the ground with chalk. The longest side is called the hypotenuse, and it's always opposite the right angle.

2. 2

   Which side is the hypotenuse in a right-angled triangle?

3. 3

   Drag the squares onto the sides of this right-angled triangle to see how they fit.

4. 4

   Let's find the missing side length: a right triangle has sides of 3 cm and 4 cm. What is the hypotenuse?

5. 5

   A right triangle has sides 6 cm and 8 cm. What is the length of the hypotenuse?

6. 6

   If a right triangle's two short sides are 5 cm and 12 cm, what is the hypotenuse?

7. 7

   Pythagoras' theorem works for ANY right-angled triangle. Just remember: a² + b² = c², where c is the hypotenuse.