We could use the distance formula but because the line is vertical, there is no need to use the distance formula.
First point is at (-1, -2) and the second is plotted at (-1, 3). We x-coordinates don't change. Just take the absolute value of the difference between the -2 and 3.
|3 - (-2)| =
|3 + 2| =
|5| = 5
So, 5 units is the answer.