2. The distance around an enclosed shape is called the perimeter. The amount of space enclosed inside a shape is called the area.

3. Area of a rectangle base height Area of rectangle = base × height

4. Area of a triangle base Area of triangle = ½ × base × height height

5. Area of a parallelogram A parallelogram can be made into a rectangle. base height Area of parallelogram = base × height

6. Area of a trapezium Two identical trapeziums can be made into a parallelogram. a h Area of parallelogram = ½ (a + b) h b b a

7. 10 8 Examples 1 Find a the perimeter b the area of the shape. All lengths are in cm. 7 6 10 8 7 6 2 3 a b

8. 10 cm 3 cm Examples 2 Find the area of the parallelogram.

9. 6 cm 4 cm Examples 3 Find the area of the triangle.

10. Examples 4 Find the area of the trapezium. All lengths are in cm. 5 3 2

11. Examples 5 The area of the trapezium is 24 cm 2. Find the value of x. 2x+3 4 cm x