Answer:
64 ft²
Explanation:
A prism is a three dimensional shape with two identical shapes facing each other known as bases. A right prism is a three dimensional solid with a polygon as its base and vertical sides which are perpendicular to the base.
Given that the first sandbox is a right prism a square base, hence this is a square prism (that is a cube).
Since the side length of the square base is 8 ft, hence the area of the base of the first sandbox is:
Area of the base = length * length = 8 ft * 8 ft = 64 ft²