Perimeter, Area and Circles

This lesson covers the essential formulae for perimeter and area of 2D shapes, as well as circles, sectors and arcs, for AQA GCSE Mathematics. Area and perimeter questions appear on every exam paper, from simple rectangles to compound shapes and circle problems. You must know all the formulae and be confident applying them in context.

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Perimeter

The perimeter is the total distance around the outside of a shape.

• For most shapes, add up all the side lengths.
• For a rectangle: Perimeter = 2(l + w), where l = length and w = width.
• For a circle: the perimeter is called the circumference.

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Area of Standard Shapes