Constructing a Square

Constructing a square whose side length is congruent to a given segment. This same technique can be used to construct a rectangle - the only difference is in the copying of the segments since a rectangle has 2 distinct side lengths.
Pre-Requisites:
Perpendicular Line Through a Point on the Line ( • Constructions - Perpen... )
Copying a Segment ( • Constructions - Congru... )