Is There a “Best” Rectangle?
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.
Sketching Up the Digital Duck
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.
Teaching the Perpendicular Bisector: A Kinesthetic Approach
Through movement—a welcome change of pace—students explore the properties of the perpendicular bisector.
The Shape of an Ellipse
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.
More on Ellipses and Polar Coordinates
Navigating between the Dimensions
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.
Stop Teaching and Let Students Learn Geometry
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.
Instructions for the EGASP
Examples of the EGASP
Recreating History with Archimedes and Pi
Lora C. Santucci
Students use modern technology to investigate historical perspectives and calculate an approximation of pi.
Thinking Deeply about Area and Perimeter
Using a 6-inch-square sheet of paper and a simple rule for creating a polygon, students can explore interesting area and perimeter problems.