Given the volume of the box is 100 cm^3
And to made the box we need to cut a square measuring 4 centimeters on a side from a square piece of cardboard.
so, the height of the box = 4 cm
so, the volume = height * area of the base
100 = 4 * area of the base
Area of the base = 100/4 = 25 cm^2
so, the side length of the base of the box =
so, the lenght of the a side of the original square = 5 + 2*4 = 5 + 8 = 13 cm