Answer:
42mm
Step-by-step explanation:
For the perimeter of a shape you would add all the sides together. So in this case it would be:
7mm+7mm+7mm+7mm+7mm+7mm=42mm
A hexagon has 6 sides and if each side measures 7mm. Your answer is 42. To get this add the measurements of all six sides together.
7+7+7+7+7+7= 42