An activity designed as an introduction to High School geometry empowering students to see relationships and make geometric connections. A list of student generated relationships based on student constructed and manipulated diagrams is included. Discussion guidelines are suggested. (DE)

Describes and gives patterns for polyhedra other than the Platonic and Archimedean solids. The focus is on the deltahedra, but pyramids, prisms, and antiprisms are discussed first to help describe the deltahedra. (PK)

With a standard geoboard, five pegs by five pegs, how many different triangles can be formed using a single rubber band with the pegs serving as vertices? Discusses ways to solve this problem and offers related problems and some pedagogical considerations (particularly for the teaching of geometry and problem solving). (JN)

Uses manipulative materials to build and examine geometric models that simulate the self-similarity properties of fractals. Examples are discussed in two dimensions, three dimensions, and the fractal dimension. Discusses how models can be misleading. (Contains 10 references.) (MDH)

Presents three teaching ideas: (1) investigating patterns in the sum of four numbers in a square array, no two from the same column or row; (2) using three-dimensional coordinates to generate models of three tetrahedra; and (3) applying the K=rs area formula for a triangle to other polygons. (MDH)

Two trigonometry problems are presented. The first compares the graphs of the functions arcsin[sin(x)], arccos[cos(x)], and the identity function f(x)=x. The second, using the law of cosines, demonstrates that the solution of a triangle knowing two sides and the excluded angle is no longer ambiguous. (MDH)

Presents lesson plans for activities to introduce recursive sequences of polygons: golden triangles, regular pentagons, and pentagrams. The resulting number patterns involve Fibonacci sequences. Includes reproducible student worksheets. (MKR)

Diagrams that illustrate characteristics that are always, sometimes, or never present in a concept can be categorized as examples or nonexamples to broaden students' understanding of basic geometric concepts. (MKR)

Describes the most enduring link between Napoleon and mathematics as the geometric result known as Napoleon's Theorem, which states that if equilateral triangles are drawn on the three sides of any triangle, the line segments joining the centers of these equilateral triangles will themselves form an equilateral triangle. (ASK)

These materials are intended to provide meaningful mathematical experiences for pre-algebra students. These experiences emphasize the development of computational skills, mathematical concepts, and problem-solving techniques. This bulletin may be used as the basis for the second term of a one-year course, or for the second year of a two-year…

Presents a geometry exercise which is designed to help students create three-dimensional clay figures, think in three dimensions, and develop vocabulary. Reproducible worksheets are included. (PK)

Gives definitions of taxicab geometry and the MacDraw format for graphing. In the world of taxicab geometry, movement through the plane is along horizontal and vertical paths. Describes specific application to conic sections, including circle, ellipse, parabola, and hyperbola. Lists five references. (YP)

A mult tile is a set of polygons each of which can be dissected into smaller polygons similar to the original set of polygons. Using a recursive LOGO method that requires solutions to various geometry and trigonometry problems, dissections of mult tiles are carried out repeatedly to produce tile patterns. (MDH)

Described is a theorem which is generally not present in most high school geometry textbooks. Presented are two proofs and two cases which illustrate the use of the SSA theorem. (CW)

Presents a lesson in which students communicate verbally and in writing to create and describe geometric transformations, develop vocabulary, demonstrate ability to give unambiguous instructions to translate a triangle, form and test conjectures, and create extensions of problems. Includes reproducible student worksheets and questions for…