#### Answer

The equation $A=4\pi r^2$ is dimensionally correct.

#### Work Step by Step

In the equation $A=4\pi r^2$,
$A$ is area and has SI units $m^2$.
On the other side, $\pi$ is a dimensionless constant;
and, $r^2$ has SI units $m^2$.
Both sides have the same SI units, and therefore, the equation is dimensionally correct.