Activities (for students)
Activities for Students: Classifying Triangles and Quadrilaterals
Orlando B. Alonso and Joseph Malkevitch
Edited by Ruth Dover and Patrick Harless
March 2013, Volume 106, Issue 7, Page 541
The classification of shapes in middle and high school geometry often seems very mysterious to students, featuring strange terms such as isosceles, trapezoids, and kites, which are defined by a mixture of parallelism and metric ideas. The activities introduce a more natural way to classify triangles and quadrilaterals.