Question

The semi-circle has a diameter of 8. What is the perimeter of the semi-circle?​

Answer 1

Approx. 20.566 units

Explanation:

Find the circumference of the whole circle first by doing:

C = 2πr

r = 4 (8 divided by 2)

C ≈ 25.133

Then divide that by two because a semi-circle is half a circle:

12.566

Then add 8 (diameter) to that number for the open side.

Hope this helps :)

Answer 2

roughly 12.56 units

Explanation:

Since the perimeter of a circle is 2*pi*r, we can divide it by two or multiply by half in order to find the perimeter of a semicircle

half of the diameter is the radius, so 8/2 =4, r=4

Plug in what we know...

C=2*pi*4

Solve

2*3.14*4

25.12

divide by 2

25.12/2=12.56

12.56 units is the perimeter