Respuesta :
Since the perimeter of the square is 40 then you will divide 40 by 4 wich will equal 10, so each side of the square is 10 mm long.
My Work:
40/4= 10
10+10+10+10=40 or 10x4=40
My Work:
40/4= 10
10+10+10+10=40 or 10x4=40