In this program we explore the properties of angles and planes. We do this in the context of two real-world applications.

The observatory in Arecibo, Puerto Rico provides astronomers insights into the structure of our solar system.

Himeji castle in Japan is a marvel of architecture and a startling example of geometry and military science.

In the Canadian Rockies, the Burgess Shale fossils provide a window to prehistoric Earth.

This cheat sheet gathers together the resources on the topic of parallel and perpendicular lines. See the descriptions and links below. Each link takes you to a collection of resources around that topic.