A few days ago
Anonymous

Math Homework??!!!!?

Okay, this is the problem:

The area of the semicircular region is 16 pi. Find the figure’s perimeter.

There is also a picture of a semicircle, but that’s it. We haven’t even gone over this in class and I have no idea how to start. I looked in the back of the book to find the answer to see if I could figure the answer out like that, but I still don’t know. The answer is approximately 29.09. Please show all the work. Thanks ahead of time!!!!

Top 1 Answers
A few days ago
Anonymous

Favorite Answer

If r is the radius of the semicircle and a is its area, then:

a = pi r^2 / 2 ….(1)

The perimeter of the semicircle is pi*r for the curved part, and 2r for the straight line. That totals r(pi + 2) …..(2)

From (1):

pi r^2 / 2 = 16 pi

r^2 / 2 = 16

r^2 = 32 = 16*2

r = sqrt(16)sqrt(2) = 4sqrt(2).

From (2), the perimeter is:

4sqrt(2) (pi + 2)

= 4 * 1.4142 * (3.14159 + 2)

= 29.09.

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