So if a circles diameter is 1 then its circumference is p. 2r 2 15 30 cm. Once you have the radius the formulas are rather simple to remember.
You can calculate the circumference of any circle if you know either the radius or diameter.
Polar coordinates for a circle with center 0 0. H and k are the x and y coordinates of the center of the circle x 9 2 y 6 2 100 is a circle centered at 9 6 with a radius of 10. A b1 b2 c Circle Radius the distance from the center to a point on the circle r. Diameter the distance between two points on the circle through the center d 2r.