When you buy a tv or computer monitor, the size is listed as a single number measurement. This number is the diagonal distance between opposite corners of the screen. For example, a 50-inch screen has 50 inches between opposite corners. Assume that the screen you just bought has a ratio of length to width of 2:1. Meaning, if its length is a, its width is 2a. What is the length and width of a 45-inch screen?