The circumference of a circle is the perimeter of the circle.

The radius of a circle is any line segment that joins the centre of a circle to its edge.

The diameter of a circle is any line segment that starts and ends on the edge of the circle and passes through the centre.

Circumference of a circle

Maths

In this unit, pupils have derived the formula for the circumference and area of a circle. In the future unit, this knowledge is combined with knowledge of fractions to find the arc length and area of a sector.

 In the prior unit, pupils learnt how to derive and use the formula for the area of a triangle and trapezium. In this unit, this knowledge is called upon to find the volume of different prisms and area of composite shapes.

Perimeter, area and volume

A circle with a diameter of 6 cm has a circumference of {{ }} cm, when rounded to 1 decimal place.

The circumference of the circle is {{ }} cm, when rounded to 3 significant figures.

Which calculation would find the radius of a circle with circumference 20 cm?

The circumference of a circle is 30 cm. The diameter of the circle is {{ }} cm, when rounded to 1 decimal place.

Starting with the smallest, sort the circles in ascending order of size.

If a circle has a diameter of 12 cm then its radius will be {{ }} cm.

$$\pi$$ is the ratio between which two parts of a circle?

Which two formulae can be used to calculate the circumference of a circle?

A circle with diameter 12 cm has a circumference of {{ }} cm.

A circle with radius 20 cm has a circumference of {{ }} cm.

This lesson will soon be taken down.

Circumference of a circle

Lesson outcome