# Geometry: Archimedes' Book of Lemmas Index

 Archimedes' Book of Lemmas- Table of Content Archimedes wrote the "Book of Lemmas" more than 2200 years ago. Solve these 15 high school level problems and lift up your geometry skills. Proposition 1. Tangent circles and parallel diameters Etching and Typography of Geometry Problem 640. Archimedes Book of Lemmas: Proposition 1 Using iPad Apps. Proposition 2 Semicircle, diameter, tangents, secant line. Proposition 3 Semicircle, perpendicular to diameter, chords. Proposition 4 Semicircles, perpendicular to diameter, Arbelos. Proposition 5 Arbelos, Archimedean Twins, Semicircles, Circles Proposition 6 Arbelos, Semicircles, Circle. Proposition 7 Square and inscribed and circumscribed Circles Proposition 8 Angle Trisection. Neusis construction. Proposition 9. Perpendicular chords, sum of arcs. Proposition 10 Tangents to a circle, secant line and chords, Parallel. Proposition 11  Perpendicular chords  and radius, square. Proposition 12 Semicircle, Diameter, Chords, Tangents, Perpendicular. Proposition 13 Circle, Diameter, Chord, Perpendicular, Congruence. Proposition 14 Salinon: Semicircles, Perpendicular, Circles, Areas. Proposition 15 Circle, Diameter, Inscribed Regular Pentagon, Arc, Midpoint, Perpendicular, Radius. Arbelos, Theorems and Problems Three tangent semicircles with collinear centers. Index