Answer
$x^2+y^2=64$
Work Step by Step
RECALL:
The standard form of the equation of a circle centered at $(0, 0)$ with a radius of $r$ units is:
$x^2 + y^2 = r^2$
Use the standard form above where $r=8$ to obtain:
$x^2 + y^2 = 8^2
\\x^2+y^2=64$
