https://docs.google.com/document/d/1b9CgQ5TIBvVpaKmtWhhIXvXhkJ6NmS0xttnYptPcrxE/edit?usp=sharing
Geometry Lab: Guess that angle, guess that slope
https://docs.google.com/document/d/1AeWIklZJZ_AlUHHj9_Y7UWK8vEJh_tHSBfHth7ZOnIg/edit?usp=sharing
Geometry Lab: Adding and Subtracting with Negatives
Geometry: Finding Equations of Parallel and Perpendicular Lines