1. Circles Yes I know we did this yesterday

2. Circumference Posh name for the perimeter of a circle Measured in normal units of length cm etc. But how do I work it out?

3. Glad you asked. First we need to remember the basics Radius pl. radii diameter

4. Get to the point. Circumference = 2πr (r = radius) = πd (d = diameter) π (pi) = 3.1416……… (goes on forever) Yes just like someone else

5. One for you to try C = 2 x π x r = 2 x π x 6 = 12 π = 37.7cm (to 1 d.p.) 6cm

6. So what about area? Measured in square units Area = πr 2 (π x radius x radius)

7. Example Area = π x 5 2 = 25π = 78.5 cm 2 (to 1 d.p.) 5cm