Antiparallelogram

As a Antiparallelogramm itself via tapping square is called, which in each case opposite, not adjacent sides have the same length and in which (in contrast to an ordinary parallelogram ) cut two sides are not parallel. In particular it is not convex. Sometimes addition of a Antiparallelogramm required that a pair of opposite sides to be in parallel.

Are the lengths of the adjacent sides of a Antiparallelogramms in proportion and keep to one of the two longer sides fixed, then the midpoint of the opposite side describes a Bernoulli lemniscate.

If you build a Antiparallelogramm as mechanical design with rigid sides and joints at the corners on, then one can thus convert linear motion into circular, so create a replacement for a connecting rod.