Students analyze a photograph to solve mathematical questions related to the images captured in the photograph. This month, two differently shaped soda containers are compared. Volumes, including volumes of revolution, are computed.
Gloriana González and Anna F. DeJarnette
An open-ended problem about a circle illustrates how problem-based instruction can enable students to develop reasoning and sense-making skills.
Michael J. Bossé and Kwaku Adu-Gyamfi
A geometry course for teachers—easily adaptable to a high school geometry class—integrates technology, reasoning, communication, collaboration, reading, writing, and multiple representations.
Zhonghong Jiang and George E. O'Brien
Using technology to explore the Three Altitudes of a Triangle problem, students devise many proofs for their conjectures.
This activity allows students to build their own understanding of what it means to develop a solid argument.
A set of problems of many types
Wendy B. Sanchez
Educating students—for life, not for tests—implies incorporating open-ended questions in your teaching to develop higher-order thinking.
Irina Lyublinskaya and Dan Funsch
Symbolic geometry software, such as Geometry Expressions, can guide students as they develop strategies for proofs.
This article presents a method for approximating π using similar triangles that was inspired by the author's work with middle school teachers. The method relies on a repeated application of a geometric construction that allows us to inscribe regular polygons inside a unit circle with arbitrarily large number of sides.