Question

(x-4)^2+(y+12^2)=17^2 what is the length of its radius

Answer 1

$(x-4)^{2} + (y+12)^{2} = 17^{2} \\ x^{2} + y^{2} = r^{2} \\ r^{2} = 17^{2} \\ \sqrt{ r^{2} } = \sqrt{ 17^{2} } \\ r=17$

Answer 2

$\text{The standard form equation of a circle is }(x-x_1)^2+(y-y_1)^2=r^2\\\\ (x-4)^2+(y+12)^2=17^2 \\ \Downarrow\\ r^2=17^2\\ r=17$