SOLUTION: http://i.imgur.com/GSOlmwX.jpg In the figure above, O and P are the center of two semicircles of radius r. If the length of the perimeter is 8π+16, what is the value of r?

Algebra ->  Expressions -> SOLUTION: http://i.imgur.com/GSOlmwX.jpg In the figure above, O and P are the center of two semicircles of radius r. If the length of the perimeter is 8π+16, what is the value of r?       Log On


   

Question 1043410: http://i.imgur.com/GSOlmwX.jpg
In the figure above, O and P are the center of two semicircles of radius r. If the length of the perimeter is 8π+16, what is the value of r?
A) 2
B) 4
C) 6
D) 8
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
pi%2Ar%2B2r%2Bpi%2Ar%2B2r+=+2%2Api%2Ar%2B4r+=+8%2Api%2B16+

===> 2r%2A%28pi%2B2%29+=+8%28pi%2B2%29
===> 2r = 8 ===> r = 4