Luca sells hand crafted puzzles for $22 each.

The formula to graph a circle is:
(x-h)^2+(y-v)^2=r^2

Step 1: find the center if the circle.
Using this equation: x^2+y^2=r^2
Step 2: calculate the radius by solving for r
Step 3: plot the radius on the coordinate plane
Step 4: connect the dots to the graph forming a round smooth circle

Step 5: replace your (h,v) with your center points and switch the signs in your equation for the formula of graphing a circle
Step 6: calculate the radius
Step 7: plot the radius points on the coordinate plane
Step 8: connect the dots to the graph of a circle