TRIANGLE: Now he's 4 cm high and 3 cm wide, like me. He's 12 square cm, so I must be half that… 6 square centimetres! And whatever shape I am it still works! RECTANGLE: You're just really embarrassing ...

The area of the rectangle is 8 cm 2. Two triangles make the rectangle. The area of one triangle is half the area of the rectangle. \(8 \div 2 = 4~\text{cm}^2\) The area of a triangle can also be ...