Area of a Semi Circle Support Page

On this webpage you will find our range of worksheets to help your child learn to work out the area of a range of semi-circles.

These sheets are graded from easiest to hardest, and each sheet comes complete with answers.

Using these sheets will help your child to:

• understand what area is;
• know how to find the area of a range of semi-circles with either the diameter or radius given;
• solve word problems involving area of semi-circles;

• Area is a measure of the amount of space inside a shape.
• It is measured in squares, so it can be square inches (in²), square cm (cm²), square feet(ft²), etc.

Area of a Semi Circle Example 1

Find the area of the circle below to 1 decimal place.

To find the area of the semi-circle, we need to square the radius first.

3 x 3 = 9.

Next we need to multiply this amount by pi (π).

9 x π = 9π

Finally we need to halve this amount.

½ x 9π = 4.5π = 14.1 (to 1dp)

So the area of this semi-circle is 14.1 cm².

Area of a Semi Circle Example 2

Find the area of the semi-circle below to the nearest square inch.

To find the area of the semicircle, we need to square the radius first.

6 x 6 = 36

Next we need to multiply this amount by pi (π).

36 x π = 36π

Finally we need to halve this amount.

½ x 36π = 18π = 56.5 (to 1dp)

So the area of this semi-circle is 57 in² to the nearest square inch.

Area of a Semi Circle Example 3

Find the area of the semi-circle below and give your answer to the nearest whole number.

To find the area of the semicircle, we need to find the radius first.

The radius is equal to half the diameter.

So the radius is half of 18 = 9 cm

Next we need to square the radius.

9 x 9 = 81

Next we need to multiply this amount by pi (π).

81 x π = 81π

Finally we need to halve this amount.

½ x 81π = 40.5π = 127.2 (to 1dp)

So the area of this semi-circle is 127 cm² to the nearest square cm.

Our Area of a Semicircle Calculator will find the area of any semicircle, if you type in a radius or diameter.

It will take whole numbers, fractions or decimal values.

The best thing about it is that it shows the working out, step-by-step.

Sheets 1A and 1B contain straightforward area word problems.

Sheets 2A and 2B contain slightly harder word problems.

We have a range of other area worksheets and support pages for a range of different 2d shapes.

Here is our selection of free printable perimeter worksheets for 3rd and up.

Using these sheets will help your child to find the perimeter of a range of shapes including rectangles, rectilinear shapes, circles, quadrilaterals and regular shapes.

The Math Salamanders hope you enjoy using these free printable Math worksheets and all our other Math games and resources.

We welcome any comments about our site or worksheets on the Facebook comments box at the bottom of every page.