Question

How do you solve this one problem?

Answer 1

Check the picture below

thus, to get the radius  $\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) &({{ -3}}\quad ,&{{ -6}})\quad % (c,d) &({{ -4}}\quad ,&{{ 8}}) \end{array}\qquad % distance value d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}$

and once you get the radius "r", plug it in at the circle's equation then

$\bf (x-{{ h}})^2+(y-{{ k}})^2={{ r}}^2 \qquad center\ ({{ h}},{{ k}})\qquad radius={{ r}}$