Equations or systems of equations can be associated with letters of the alphabet printed in the coordinate plane. Messages can be coded and decoded with a computer or by hand. (SD)

A method is given for the analysis of geodesic domes involving plane geometry. The method shows how to calculate all necessary angles and chords, given the length of one side. (MP)

A series of maps is presented for coloring with the fewest possible colors. (SD)

This monthly column contains teaching suggestions on: using codes to convey information, flow proofs in geometry, and volleyball and probability. (MP)

Explores applications of the Fibonacci series in the areas of probability, geometry, measurement, architecture, matrix algebra, and nature. (MDH)

Discusses six examples that discover supplementary geometry theorems by using three elementary theorems about the relationships between angles and intercepted arcs in circles. Topics in the examples include angles formed by parallel lines and the sum of the interior angles of triangles, convex quadrilaterals, star polygons, and hexagons. (MDH)

Some geometric activities are described that teachers can use to give their students experiences that will influence their spatial abilities. It is noted that the goal is to improve spatial abilities, not to increase knowledge, so individual pupil responses should not be used to judge student achievement. (MP)

A description of a planet in the shape of a cube where everything was built from squares and parts of squares is presented. The story is used as a background for several paper folding exercises that explore several geometric shapes. Solutions to the problems stated are included. (MP)

Several activities that can be used to give children more experience with triangles are submitted. By handling triangular shapes and building triangles with strips, pupils can experience a diversity of triangles in a very concrete way. Examination of triangles and nontriangles can help develop understandings of some inequalities. (MP)

This activity involves students investigating the mathematics of packaging and exploring various concepts in geometry, including area and the Pythagorean theorem. Mathematics comes out of the discussion of packaging cans into six-packs and focuses on the cost-effectiveness of the horizontal storage area used. Students learn how knowledge of…

Provided is a set of six activities demonstrating how mathematical connections can be made using the concept of rectangle. The activities relating rectangle to factoring whole numbers, prime numbers, and calculating the area of rectangles, triangles, parallelograms, and circles, are also connected to each other. (MDH)

Ritzville Pyramids are cone-shaped piles of wheat found near the community of Ritzville, Washington. Presents the practical problem of determining the volume and surface area of a Ritzville pyramid to help farmers solve cost-effectiveness questions related to selling the wheat. (MDH)

Study of circular transformation and its associated properties is proposed as review and reinforcement of familiar concepts and for developing broader understanding of transformations. Inversion on a circle is discussed in some detail. (MNS)

Features articles about physical therapy and its history as related to geometry through measurement of body angles. Includes open-ended worksheets for mathematics activities that introduce students to angle measurement, data analysis, and mathematical tools. Activities include: (1) Making Your Own Goniometer; (2) Range of Motion; (3) Active versus…