Why are summer days longer than winter days? How far away is center field? Will my car fit in that parking spot? If you have questions about length, area, or volume, geometry textbooks have the answers. From the Pythagorean theorem to Pi, the fundamental concepts, theories, and equations associated with geometry are covered in this subsection of mathematics textbooks. With an emphasis on logic and reasoning, college geometry courses are usually prerequisites for trigonometry and calculus.