R. Alan Russell
In trying to find the ideal dimensions of rectangular paper for folding origami, students explore various paper sizes, encountering basic number theory, geometry, and algebra along the way.
Kathryn G. Shafer, Gina Severt, and Zachary A. Olson
Two preservice teachers describe how using Google SketchUp, Terrapin Logo, and The Geometer’s Sketchpad fosters a deeper understanding of measurement concepts.
Ayana Touval
Through movement—a welcome change of pace—students explore the properties of the perpendicular bisector.
Gregory D. Foley
Ellipses vary in shape from circular to nearly parabolic. An ellipse’s eccentricity indicates the location of its foci, but its aspect ratio is a direct measure of its shape.
Julian F. Fleron and Volker Ecke
Two classroom activities—the Flatland game and sliceforms—are useful vehicles for student exploration of the geometric interplay between the dimensions.
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.
Lora C. Santucci
Students use modern technology to investigate historical perspectives and calculate an approximation of pi.
Wayne Nirode
Using a 6-inch-square sheet of paper and a simple rule for creating a polygon, students can explore interesting area and perimeter problems.