Start with the video below to get an overview of the big ideas for this chapter.
***What are the possible shadows of a square?***
In our third chapter, this seemingly straightforward question will lead us deep into the heart of projective geometry, where we will uncover the fundamental properties of our perspective shifting maps.
## [Lecture 7: A Closer Look at Perspectivities](./lecture-7.html)
## [Lecture 8: Projectivities and the Three-Fixed Points Theorem](./lecture-8.html)
## [Lecture 9: The Fundamental Theorem of Projective Geometry](./lecture-9.html)
