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.

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?

This lesson will soon be taken down.

Using the formula for the area of a circle

Lesson outcome