Distância entre retas no espaço

Synopsis: In this lecture we discuss the notion of distance between straight lines in space. The novelty with respect to the planar geometry is in the case of the distance between reverse straight. But also in this case, we see that this distance is given by a plane perpendicular to both straight segment. We illustrate the concept in situations in cube and regular tetrahedron.
Source: Portal of Mathematics.
URL: http://matematica.obmep.org.br/index.php/modulo/ver?modulo=27&tipo=1#