Students learn about finding the circumference of a circle as a multiple of π and as a decimal correct to 3 significant figures. As learning progresses students are challenged to find the perimeter of semi-circles and sectors.

At the start of the lesson students recap finding the perimeter of complex shapes using a right-angled triangle. The plenary challenges students to apply their learning to a real work problem.

**Differentiated Learning Objectives**

- All students should be able to find the circumference of a circle as a multiple of pi when the diameter is given.
- Most students should be able to find the circumference of a circle to 3 significant figures.
- Some students should be able to calculate the arc length of a sector.