9.6

Equation for a circle with the center at the origin: x²+y²=r²
 * Equations:**

x and y are always at (0,0) and the the radius varies. Equation example: x²+y²= 25 the radius is five while the center is at (0,0) [|This link] will show you what a circle with is center at the origin is.

Equation for a circle with the center not on the origin: (x-h)²+(y-k)²=r²

//(x-5)²+(y-3)²=16

the circle is at (5,3) and the radius is at// //4.//