This is a short video guide that I use with a Khan Academy Video on Geometry. The video is about 13 minutes long - I usually use it to introduce the basic terms of geometry and how to distinguish between line, ray, segment, etc. when writing about them. The url for the video is written on the guide, and is also written below:

https://www.khanacademy.org/math/basic-geo/basic-geo-lines/lines-rays/v/language-and-notation-of-basic-geometry

The guide just helps students stay on-task while watching the video. They seem to enjoy having something to fill in based on the video, and it helps hold them accountable for the content.