if the diameter is 26 yards, then its radius is half that, or 13 yards.
[tex]\bf \textit{circumference of a circle}\\\\ C=2\pi r~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=13 \end{cases}\implies C=2\pi (13)\implies C=26\pi \implies C\approx 81.68 \\\\[-0.35em] ~\dotfill\\\\ \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=13 \end{cases}\implies A=\pi (13)^2\implies A=169\pi \implies A\approx 530.93[/tex]
