This document provides information about circles and some circle theorems. It begins with definitions of basic circle terminology like radius, diameter, chord, arc, and sector. It then presents five circle theorems without proofs: 1) If two arcs are congruent, their chords are equal; 2) The perpendicular bisector of a chord passes through the center; 3) The line from the center to the midpoint of a chord is perpendicular to the chord; 4) There is only one circle passing through three non-collinear points; 5) The angle subtended by an arc at the center is double the angle at any other point on the remaining part of the circle. Sketch proofs are provided for theorems 2 through 5