Question

Work out the perimeter of a semicircle with the radius of 3

Answer 1

`6\pi + 6`

Explanation:

The circumference of a circle is defined as:

• 
  `C=2\pi r`

where
`r` is the circle's radius and
`\pi` is a constant approximately equal to
`3.14`.

To find the perimeter of a semicircle, we can multiply the circumference of a circle with the same radius by 1/2, then add the diameter (
`2r`):

`P _\text{semi}= C_\text{whole} + 2r`

↓ rewriting with the circumference definition

`P _\text{semi}= 2\pi r + 2r`

↓ plugging in the given radius of 3

`P _\text{semi}= 2\pi (3) + 2(3)`

↓ simplifying the multiplication

`\boxed{P _\text{semi}= 6\pi + 6}`