Home

Power of a Point Theorem Calculator

Online point-and-circle checker. Enter the distance d to the center and radius r to locate the point (outside/on/inside) and compute its power—ideal for circle power.

展开更多 ▾
Power=D²−r²; positive outside, 0 on, negative inside
P
Point-to-center distance
Radius

📖 Tutorial | Point and Circle

1. Definition
Compare the distance D to the radius r to locate the point.
2. Formula & Notation
D, rDistance and radius
PowerD²−r²
3. Properties & Laws
  • D>r outside, =r on,
  • Outside power positive = tangent²;
  • On the circle it is 0;
  • Inside it is negative.
4. Steps
  1. Enter D and r;
  2. Click "Decide";
  3. Or click "Load Example".
5. Worked Examples
Example: D=7, r=5.
Solution: outside, power = 24.
6. Common Pitfalls
Positive outside, negative inside;
D can be 0;
Power = tangent².

❓ FAQ | Point and Circle

How to locate?
Compare D with r.
Power?
D²−r².
D=7,r=5?
Outside, power 24.
Outside meaning?
Tangent length squared.
Inside?
Negative.
On the circle?
0.