Originally Posted by

**frick** The distance from (-101, -159) to (-152, 62) is $\displaystyle \sqrt{(-101+ 152)^2+ (-159- 62)^2}= \sqrt{51^2+ (-221)^2}= \sqrt{51442}= 226.81$.

That is the diameter of the circle and the circumference is $\displaystyle \pi$ times the diameter (there is no reason to divide by 2 to get the radius.

Using "$\displaystyle c= 2\pi r$ you would just multiply by 2 again.) so is $\displaystyle 3.1416(225.81)= 712.59$ which, rounded up to a whole number

is 713, **not** "717". I have no idea why they have the "$\displaystyle \pm 1$%". There is nothing said about an error in the measurement. "