Question

The circle below is centered at the point (8,4) and has a radius of length 4 what is the equation

Answer 1

$\bf \textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{8}{ h},\stackrel{4}{ k})\qquad \qquad radius=\stackrel{4}{ r} \\\\[-0.35em] ~\dotfill\\\\ (x-8)^2+(y-4)^2=4^2\implies (x-8)^2+(y-4)^2=16$