Answer :
[tex] (x-4)^{2} + (y+12)^{2} = 17^{2} \\ x^{2} + y^{2} = r^{2} \\ r^{2} = 17^{2} \\ \sqrt{ r^{2} } = \sqrt{ 17^{2} } \\ r=17[/tex]
[tex]\text{The standard form equation of a circle is }(x-x_1)^2+(y-y_1)^2=r^2\\\\
(x-4)^2+(y+12)^2=17^2 \\
\Downarrow\\
r^2=17^2\\
r=17[/tex]
