Use the formula C=2pi to find the radius, r, for a circle with a circumference of 160 centimeters. Round your answer to the nearest hundredth.

a) 50.96 cm
b) 28.08 cm
c) 25.48 cm
d) 80.00 cm

When I tried to solve this problem, I never got any of these answers; I got 251.32, approx. Can you show me the correct answer and how you got it? Thanks! :)

3 answers

Hmmm. Did you wonder why the radius of the circle was bigger than the circumference? That can't be, at least here in Texas.

C=2Pi*r
r=C/2PI
Yes, that is the equation that I'm using, but it's still not working, I don't understand why.
Multipy 2*PI= 6.28..
divide that into 160
In my head, six into 160 is about 26