A circumscribed polygon is a polygon that is surrounded by a circle, meaning all its vertices touch the circle. This circle is known as the circumcircle, and its center is called the circumcenter. The properties of circumscribed polygons are important in geometry, particularly in the study of triangles and other shapes. In a circumscribed polygon, the sides of the polygon are not necessarily equal in length, but the angles can be related to the circle's radius. For example, in a circumscribed triangle, the circumcircle passes through all three vertices, making it a key concept in triangle geometry.