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.
TOPEX/Poseidon is a satellite that measures the precise shape of the ocean's surface and how this surface changes through time. This helps the scientists to calculate ocean currents, identify climate trends, and improve weather forecasting models. A recently observed climate trend is the Pacific Decadal Oscillation.