Definition:Compass

Definition
A compass is an ideal tool for drawing circles.

Hence it can be used according to Euclid's third postulate to construct a circle using any two given points:
 * $(1): \quad$ the center

and:
 * $(2): \quad$ an arbitrary point on the circumference.

Also see

 * Definition:Compass and Straightedge Construction
 * Definition:Rusty Compass