Wentworth's Plane and Solid Geometry
Definitions, axioms and proved propositions in nine books, plane and solid, with hundreds of exercises.
Scanned by Google from a Harvard University copy.
Homeschool · Math
Geometry
Wentworth's Plane and Solid Geometry, the standard American geometry textbook around 1900, free to read here or download. Teaching guides are on the way.
About the book
George A. Wentworth (1835–1906) taught mathematics at Phillips Exeter Academy and wrote a long series of school math books for Ginn. His geometry teaches the subject the classical way, as a chain of definitions, axioms and proved theorems, with many original exercises for the student to prove. It suits students of about 13 and up who are comfortable with arithmetic and a little algebra.
Plane geometry (Books I–V) covers lines, angles, triangles, circles, proportion, areas and regular polygons. Solid geometry (Books VI–IX) covers planes, solids, the cylinder, cone and sphere. A ruler and compass are all the tools you need, and the site's graphing calculator is handy for checking numbers.
The book
Wentworth's Plane Geometry
The first five books on their own, a lighter volume if you only want plane geometry.
Scanned by Google from a New York Public Library copy.
About these copies
Every book here was published in the United States before 1930, so it is in the public domain there: free to read, print and share. The scans are kept by the Internet Archive, which shows them on this page and supplies the PDF downloads. The teaching guides are written for this site. Modern reprints are also sold, if you prefer a clean printed copy.