Sheila is climbing on a ladder that is attached against the side of a jungle gym wall. she is 7 feet off the ground and is 5 feet from the base of the ladder, which is 25 feet from the wall. how high up the wall is the top of the ladder?

3/4 = h/15 

This assumes that she is 5 feet up the ladder, or 4 feet closer to the ground. 

If she is in fact 5 feet closer to the ground, then the original answer is good. The wording of the problem is unclear.Assuming that she is 5 feet along the ladder, then using similar triangles, 

3/5 = h/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 : )