Answer:
15.9 centimeters
Step-by-step explanation:
the information we have is:
Perimeter: 
Number of sides of the polygon: 
since each side has equal length, we can use the following equation to find the measure of one side of the polygon, the equation for perimeter:

where n is the number of sides and
is the length of each side.
So we clear for
and we get:

and subtituting the known values:

each side is 15.6 centimeters long