Historical accounts of trigonometry refer to the works of many Indian and Arab astronomers on the origin of the trigonometric functions as we know them now, in particular Abu al-Wafa (ca. 980 CE), who determined and named all known trigonometric functions from segments constructed on a regular circle and later on a unit circle (Moussa 2011;…

This article describes a hands-on approach to learning proofs by induction. Students create patterns of dominos so that when the first domino is pushed, the entire design collapses, one domino at a time. Students then build designs that do not work. By constructing a list of conditions that ensure a given pattern will collapse, students discover…

An eighth grade algebra class used graphing calculators to simulate ecosystems. One simulation introduced mathematical chaos. The activities exposed the students to nonlinear patterns and modeling. The rate-of-change investigations related the ideas of intercept and slope to the changing equilibrium. The chaotic model intrigued them and was useful…

Presents activities in which students study exponential growth and decay by collecting data, constructing graphs, and discovering algebraic formulas. (MKR)

Presents cost analyses of building a patio, incorporating manipulatives, pattern building, graphing calculators, matrix applications, and functions. Includes reproducible student worksheet. (MKR)

Presents a geometric discovery involving the use of a trapezoid as a base for a pyramid. Includes reproducible student worksheet to be used as a group-discovery exercise. (MKR)

Explores trapezoidal numbers, which are the result of subtracting two triangular numbers. Includes classroom activities involving trapezoidal numbers to help students develop their problem-solving skills. Includes reproducible student worksheets. (MKR)

Presents an alternate approach to teaching quadratics by fully integrating the study of quadratic equations and quadratic functions using graphs. Includes reproducible student worksheets. (MKR)

Presents a teacher's guide and reproducible student worksheets to develop the procedure for finding the inverse of a function. (MKR)

Presents an activity, including worksheets, that introduces the ideas behind CAT scanners and explains how they are used in medical research and diagnosis. (MKR)

Cooperative groups were given transparencies of eight regular inscribed polygons and overlays of corresponding circumscribed polygons and were asked to find the perimeters and ratios of perimeter to diameter. Transparencies give students a graphic illustration of limits. Includes reproducible worksheet. (NI)

Describes three activities in discrete mathematics that involve coloring geometric objects: counting colored regions of overlapping simple closed curves, counting colored triangulations of polygons, and determining the number of colors required to paint the plane so that no two points one inch apart are the same color. (MKR)

Explains standard drawing layouts and rules for creating orthographic and isometric views of a three-dimensional object. Normal and inclined surfaces are also discussed. Concludes with recommended classroom activities. Includes reproducible student worksheets. (FDR)

Worksheets contain instructions and patterns for use in constructing models of the platonic solids from cardboard and rubber bands. (SD)

These worksheets involve the use of tangram pieces in creating geometric shapes and in analyzing properties of convex quadrilaterals. (DT)