Answer
$5600$ millimeters
Work Step by Step
Since in each 1 meter there are 1000 millimeters, we will have to convert meters into millimeters.
Thus, 1000 millimeters$=1$ meter
Now, we have
$ 5.6 \text {meters} \times \dfrac{1000 \text {mm}}{1 meters} =5600$ millimeters