Geometry
# Properties of Triangles

From Euclid to Euler, triangles have been the focus of mathematicians for millennia. Although they may be simple to visualize, the laws that govern their properties are rich with geometric knowledge. Start this chapter to unlock the powerful underlying theorems.

In this chapter, you can expect to see and learn how to solve questions like this one:

If you want to jump right in, **concept quizzes** train you on a specific technique in triangles, while the **challenge quizzes** are slightly harder and test your knowledge from a variety of the ideas learned in the concept quizzes.