Area is the size of the surface and states the number of unit squares needed to completely cover that surface.

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.

Using the formula for the area 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.

In this unit pupils extend their knowledge of shapes by exploring the properties of circles and composite shapes before developing understanding of 3-D shapes including surface area and volume.

Perimeter, area and volume

The area of a circle can be calculated by multiplying $$\pi $$ by the square of the {{}}.

A circle has radius 10 cm. Its area is {{}} cm$$^2$$, when rounded to 3 significant figures.

The distance from the centre of a circle to its edge is 12 cm. The area of the circle is {{}}$$\pi$$ cm$$^2$$.

The area of a circle is 80 cm$$^2$$. The radius is {{}} cm, when rounded to 3 significant figures.

The area of a circle is 150 cm$$^2$$. The diameter is {{}} cm, when rounded to 3 significant figures.

furthest distance from one side of a circle to the other

any line segment from centre to circumference of circle

Match the parts of a circle with their descriptions.

What is 10$$\pi$$ as a decimal rounded to 3 significant figures?

Evaluate the expression $$5x^2$$ when $$x=2$$.

Which is the formula for the area of a circle?

Starter Quiz