And in that 360 degree turn, there are ten bases. And that means every time we go from one base to another, there's an angle change in 36 degrees, because 36 divided by ten gives us 36 degrees. So every single time we go from, let's say, this base pair down to this base pair, the DNA turns by 36 degrees. And when we go down ten of these base pairs, our degree measure is 36 times ten or 360 degrees. Now, the final observation they are able to deduce following these X ray diffraction patterns is the fact that the entire diameter of this DNA molecule is 20 angstroms. Now, what about the base pair?