points of circle

[mabbia]

i want to write a program that determine if a point (a,b) lies on the circle, inside the circle or outside the circle. center and radius are given..plz help me with this one.

[ShodanHo]

Compute the distance from the centre of the circle.
if greater than,equal to, or less than the radius of the circle, then it is outside,on, or inside the circle.

[ritstudent]

Adding to what ShodanHo said:
http://www.purplemath.com/modules/distform.htm