Answer
See image:

Work Step by Step
Conversion formulas: $\left\{\begin{array}{ll}
(x,y)=(r\cos\theta,r\sin\theta) & \\
r^{2}=x^{2}+y^{2}, & \tan\theta=\frac{y}{x}
\end{array}\right.$
$r$ is the distance of the point from the pole.
$r=2$ defines all points at a distance of 2 units from the pole.
So, $0\leq r\leq 2$ describes all points on or inside the circle of radius 2
In Cartesian coordinates,
$x^{2}+y^{2}\leq 4$