Question

What is the circumference of the semicircle in this figure?





9.42 ft

37.68 ft

4.71 ft

18.84 ft

Answer 1

Can you please explain the steps!

Answer 2

Well let's look at it as if it were an entire circle.

Also, we know that Circumfrence = 2pi(r) or C = 2 * pi * r

So looking at the half circle, it looks like the diameter is what? Can you tell?

Answer 3

The diameter is shown on the left side of the figure as 3.

This means we know that the radius is half of that, or 1.5, right?

Answer 4

So with r = 1.5

We can say C = 2 * pi * 1.5
C = 3pi

Now you need half the circumference (which isn't a circumference at all but a half circle arc) which is
1/2C or 1/2(3pi)

So you distance of the half circle is 3/2pi

Answer 5

Note: The 12ft length is extraneous information meant to confuse you a bit and is not needed for the solving of this problem.