Answer
A solid sphere with radius 2 and center at the origin.
Work Step by Step
$x^2+y^2+z^2 = r^2$ is our given formula for a sphere.
Adjusting this to $x^2+y^2+z^2 \leq r^2$ tells us we are only working with points contained on or within the sphere.
When $r^2 = 4$, $r= 2$.
