Problem number 3 states, a cube with an edge of 1 is cut into two identical cuboids. What is the surface area of one of these cuboids? So we have our cube here, and we know that it has side lengths of 1. In this case we'll say centimeters, but they can be whatever unit you want, even nautical miles. So there's only one way to cut this cube such that the result is two identical cuboids, and that is in half like this. Since the side length is cut in half, that means the edge length of the new cuboid is going to be half a centimeter. The question asks for the surface area of only one of the cuboids, so let's only consider this one. We would have two of these kinds of face, which we will call A. The area of face A is base times height, so it would be 1 centimeter times 1 centimeter. The surface also consists of four copies of this face, which we will call B. The area of face B is also base times height, and it is 1 centimeter by half a centimeter. So now let's simplify our expression. We get 2 plus 4 times 1 half, so 2 plus 2, for a surface area of 4 units squared. So the question asks us, what is the surface area of one of these cuboids? The answer is 4, letter D.

cube

cuboid

surface area

geometry

mathematics