Finding the better fence

Given are two fence designs. Both are available for arbitrary value of x. Now the density of a fence is defined as the total length of the wire per square meter. It measures how expensive the fence is. The coarseness of a fence is the length of the longest straight line you can find inside the fence plane intersecting the wire only at the two endpoints.
If you look at the two designs, both for coarseness 10cm, which one has the smaller density?

Erich Prisner, August 2003