Topic: The Seifert-van Kampen Theorem

Wedges of Surfaces and Free Product Presentations

Wedges of Circles and Free Groups

The Torus Group from a Square

The Seifert-van Kampen Theorem

The Loop-Subdivision Proof of Van Kampen

The Klein Bottle Group from Polygon Gluing

The Genus Two Surface Group

The Fundamental Group of the Projective Plane

Simply Connected Intersections and Free Products

Presentations for Closed Orientable Surfaces