well, we know the circumference is 14π, thus
[tex]\textit{circumference of a circle}\\\\ C=2\pi r~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ C=14\pi \end{cases}\implies 14\pi =2\pi r\implies \cfrac{14\pi }{2\pi }=r\implies 7=r \\\\[-0.35em] ~\dotfill\\\\ \textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{-3}{ h},\stackrel{-8}{ k})\qquad \qquad radius=\stackrel{7}{ r} \\\\\\\ [x-(-3)]^2+[y-(-8)]^2=7^2\implies (x+3)^2+(y+8)^2=49[/tex]
