Answer :

We have that the circumference of a circle can be represented with the following equation:

[tex]C=\pi d[/tex]

where d represents the diameter of the circle.

In this case, we have a circle of circumference C = 30 ft made with the lights, then, using the equation and solving for d, assuming that pi equals 3.14, we get:

[tex]\begin{gathered} 30=(3.14)d \\ \Rightarrow d=\frac{30}{3.14}=9.55\approx10ft \end{gathered}[/tex]

therefore, the approximate diameter of the largest circle is 10 ft