In how many ways can a 2 x n rectangular checkerboard be tiled using 1x2 and 2x2 pieces

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 : )

There should only be 1 solution

Xis -1/2
y is 35/4.

Equatorial triangle and obtuce angle