Grade School Triangles
Abstract
In grade school, students learn a standard set of Euclidean triangles. Among this set, the usual 45-45-90 and 30-60-90 triangles are the only right triangles with rational angles and side lengths each containing at most one square root. Are there any other such right triangles? We answer this question completely and present an elegant complement called Ailles' rectangle that deserves to be in every geometry teacher's toolkit.
Repository Citation
Calcut, Jack S. 2010. "Grade School Triangles." American Mathematical Monthly 117(8): 673-685.
Publisher
Mathematical Association of America
Publication Date
10-1-2010
Publication Title
American Mathematical Monthly
Department
Mathematics
Document Type
Article
DOI
https://dx.doi.org/10.4169/000298910X515749
Keywords
Mathematics
Language
English
Format
text