What is the equation of the flower garden represented on the blueprint?

Given: a rectangleis given .
Find : equation of flower garden represents the blue point.
Explanation:
the center of the circle is
[tex](\frac{10+0}{2},\frac{40+0}{2})=(5,20)[/tex]and the radius of the circle is 60 feet.
so the equation of the folwer garden will be .
[tex](x-5)^2+(y-20)^2=60^2[/tex]