The "Power of a Point" theorem is a fundamental concept in geometry, particularly in the study of circles. It provides a relationship between the distances from a point to acircle and various segments created by lines related to that circle.
The power of a point P relative to a circle with center O and radiusr is OP2−r2. If a line through P meets the circle at A and B, the product of the directed distances PA and PB equals this quantity.
