Geometry check my answer?
posted by Skye on .
Wilbur Wrong is flying his remote control plane in a circle with a radius of 28 meters. His brother clocks the plane at 16 seconds per revolution. What is the speed of the plane? Express your answer in meters per second. The brothers may be wrong, but you could be right!
my work.
c= pi*d
c=28* 3.14
c=175.84
speed= distance over time
speed= 175.84 divided by 16
speed = 10.99 meters per second
Am I right? Please correct me because I was not at school for a few days so I missed lots of math class! And we have a test on Monday!

28 was the radius, not the diameter.
c = 2 pi R = 2 * 3.14 * 28 
The answer is correct.
However, you need to correct the step
c=28* 3.14
to
c = (2*28)* 3.14
which corresponds to the formula c = πd. 
Thanks so much!
c=56*3.14 :)