Question

Find the perimeter of the figure at the right.

Answer 1

The perimeter of the figure is 82.275cm.

In order to find this, we must first find the length of the arc portion. For this we will use circumference of a circle formula and then cut the amount in half (since it is a semi circle). The formula is below:

2
`\pi`r = C

We know the radius is 9 since it is half of the 18 that is the full diameter.

2
`\pi`(9) = C

28.275 = C

Now we add that to the 3 other sides, which are all 18.

28.275 + 18 + 18 + 18 = 82.275