How do you solve for radius in a circle?

So for example, if i have a circle with a diameter (length all the way across the circle) of 30, to find the radius (length 1/2 way across) i would have to divide my diameter by 2, which in this case would be 30/2 (30 divided by 2).
So my answer would be 15.

Skew lines(segments) are lines(segments) in 3 dimensions that do not intersect the given segment and are not parallel to it.  ae, bf, eg, and fh are your skew segments.  i hope that : )