You mean what Is the circumference of a circle? pi*(r)squared.
radius
A little R in a circle usually means "registered trademark".
A circle does not have a circumstance. Assuming that you mean circumfernece, the answer is c = 2*pi*r
If you mean the circumference or "perimeter": C = 2(pi)r, where r is the radius of the circle
Symbol for "registered trademark"
that symbol means trademark
if you mean an arc, then pi x r
registered trade mark ®
R means radius because the area of a circle = pi*radius2
That's the formula for the area of a circle.
The area of the circle becomes 9 times the area of the original circle. Original circle = Pi * (r ^ 2) = Pi * r * r New Circle = Pi * ((3 * r) ^ 2) = Pi * 9 * r * r