It is 2x and 4y, so you need to use pythagorean theorem. 2 squared is 4, and 4 squared is 16. Add them, and you get 20. The problem is that that won't square to a whole number, so the closest I can get it is the square root of 20, or 2 root 4.
A net is a pattern made when the surface of a three-dimensional figure or solid is laid out flat showing each face of the figure. It is then possible to use the net to calculate the surface area of the solid.
Surface Area of a Cube using Nets
A cube is a three-dimensional figure with six matching square faces.