Hans makes a wooden puzzle in the shape of a cube. If a single side of the cube is 3.5 inches, what is the surface area of the cube?
The surface area of a cube can be calculated by finding the area of each of the six faces and adding them together.
Since each side of the cube is 3.5 inches, the area of each face is 3.5 * 3.5 = 12.25 square inches.
Therefore, the surface area of the cube is 6 * 12.25 = 73.5 square inches.