Polygons are 2-dimensional shapes. They are made of straight lines, and the shape is closed (all the lines connect up).
Rectopexy is a surgical procedure used to correct rectal prolapse, a condition characterized by a weakening of the muscles that hold the rectum in place. Though the exact cause of this problem is unknown, there are several conditions that may contribute to its development.
A rectifier is an electrical device that converts alternating current, which periodically reverses direction, to direct current, which flows in only one direction. The process is known as rectification, since it straightens the direction of current. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, stacks of copper and selenium oxide plates, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Histori