Question

Work out the area of this semicircle.

Take to be 3.142 and write down all of the digits given by your calculator.
18 cm

Answer 1

A = 127.251 cm²

Explanation:

the area (A) of a circle is calculated as

A = πr² ( where r is the radius )

the area (A) of a semicircle is then

A =
`(1)/(2)` πr²

given diameter = 18 then r = 18 ÷ 2 = 9 cm , so

A = 0.5 × 3.142 × 9² = 0.5 × 3.142 × 81 = 127.251 cm²