How do you solve equations in circles?

Answer 1

Circles have the general equation (x-h)2 + (y-k)2 = r2

where (h,k) will be the center of the circle on a graph and r is its radius.

If the circle is centered at the origin h=k=0 and the equation simplifies into

x2 + y2 = r2

'Solving' implies that you know certain conditions. You substitute those into the appropriate equation and solve for the unknown.