Algebra is important for programming because it introduces the idea of variables, which is fundamental to programming in C++. But it's also important because of its general flow and structure, because of the value of parentheses, and specifically because inequalities teach us a lot about the comparison of numbers in both accurate terms as well as with regard to a range. During the course of programming, the comparison of data in terms of a range of values will be an invaluable tool. The next topic of mathematics to consider is not as useful to a general programmer as the basic mathematics and algebra seen so far, but is particularly useful for the game programmer. The next chapter considers geometry, trigonometry, and linear algebra.