Question

Find the area of a circle having a circumference of 23 units. Round to the nearest tenth.

Answer 1

`42.1\ units^2`

Explanation:

step 1

Find the radius of the circle

we know that

The circumference of a circle is

`C=2\pi r`

we have

`C=23\ units`

assume

`\pi =3.14`

substitute the given values and solve for r

`23=2(3.14) r`

`r=23/6.28`

`r=3.66\ units`

step 2

Find the area of the circle

The area of the circle is

`A=\pi r^(2)`

we have

`r=3.66\ units`

`\pi =3.14`

substitute

`A=(3.14)(3.66)^(2)`

`A=42.1\ units^2`