In
geometry,
circle power (or the
power of a circle) is the
power of a point with respect to a given
circle. In more specific terms, the power of a point
A for a circle of radius
r and center
O is defined as:
- p ≡ AP × QA
where P and Q are the points forming a line with A and intersecting the circle. This can also be expressed as
- p = AO² − r²
Note that p is actually independent of the specific line APQ.
External links