The American Mathematical Association of Two-Year Colleges
 
Some Unusual Expressions For the Inradius of a Triangle by:

Thomas J. Osler &
Tirupathi R. Chandrupatla

Tom Osler, professor of mathematics at Rowan University, is the author of 58 mathematical papers. In addition to teaching university mathematics for 43 years, Tom has been competing in long distance running races for the past 50 consecutive years. He is the author of two books on running.
E-mail: Osler@rowan.edu

Tirupathi R. Chandrupatla is professor of mechanical engineering at Rowan University. His areas of interest include finite-element analysis, design, optimization, and manufacturing engineering. He is author of the books Introduction to Finite Elements in Engineering and Optimization Concepts and Applications in Engineering, both published by Prentice Hall and used in universities throughout the world. He recently won a prestigious award for his book of Indian poetry.
E-mail: chandrupatla@rowan.edu

Several formulae for the inradius of various types of triangles are derived. Properties of the inradius and trigonometric functions of the angles of Pythagorean and Heronian triangles are also presented. The entire presentation is elementary and suitable for classes in geometry, precalculus mathematics and number theory.

 

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