Reynolds B. College Geometry. Using the Geometer's Sketchpad 2012

Textbook in PDF format

From two authors who embrace technology in the classroom and value the role of collaborative learning comes College Geometry Using The Geometer's Sketchpad. The book's truly discovery-based approach guides readers to learn geometry through explorations of topics ranging from triangles and circles to transformational, taxicab, and hyperbolic geometries. In the process, readers hone their understanding of geometry and their ability to write rigorous mathematical proofs.
Using The Geometer’s Sketchpad
Constructing → Proving
Mathematical Arguments and Triangle Geometry
Circle Geometry and Proofs
Analytic Geometry Taxicab Geometry
Finite Geometries
Transformational Geometry
Isometries and Matrices
Symmetry in the Plane
Hyperbolic Geometry
Projective Geometry
Appendixes
Trigonometry
Calculating with Matrices