Wikijunior has created a free geometry wikibook for the elementary level that’s a great introduction to geometry for all ages.
The 72-page book, Geometry for Elementary School, covers basic information such as points, lines, symmetry, congruence, how to bisect an angle and the Pythagorean Theorum. It is intended for beginner readers, meaning any age will be able to easily understand the concepts.
It is illustrated with color drawings and examples of key concepts.
The book can be printed (the print version will not contain the margin material or other unnecessary parts) or downloaded as a PDF file. It can also be read page by page online via the web.
Wikijunior describes its mission as:
The aim of this project is to produce age-appropriate non-fiction books for children from birth to age 12. These books are richly illustrated with photographs, diagrams, sketches, and original drawings. Wikijunior books are produced by a worldwide community of writers, teachers, students, and young people all working together. The books present factual information that is verifiable. You are invited to join in and write, edit, and rewrite each module and book to improve its content. Our books are distributed free of charge under the terms of the Creative Commons Attribution-ShareAlike License.
The following simple materials are necessary to use the book:
- A protractor
- A compass
- A ruler
- Graph paper
- Single-lined paper
Be sure to check out Wikijunior’s other free nonfiction titles as well.