Textbook in PDF format

Euclid. Incidence Geometry. Axioms for Plane Geometry. Angles. Triangles. Models of Neutral Geometry. Perpendicular and Parallel Lines. Polygons. Quadrilaterals. The Euclidean Parallel Postulate. Area. Similarity. Right Triangles. Circles. Circumference and Circular Area. Compass and Straightedge Constructions. The Parallel Postulate Revisited. Introduction to Hyperbolic Geometry. Parallel Lines in Hyperbolic Geometry. Epilogue: Where Do We Go From here? Appendices