This instructor's guide consists of materials for use in teaching a course in geometry designed for students enrolled in postsecondary vocational or technical education programs. Covered in the individual units of the guide are the following topics: basic terms, straight line combinations, angular conversion, circles, polygons, and geometric…

Describes activities that use the geometric construction capabilities of the Geometer's Sketchpad computer software to explore triangles. Topics investigated include angle measurement, the sum of the measures of the angles of a triangle and a five-pointed star, triangle classification, and area and perimeter of a triangle. (MDH)

Describes the process of combining two theorems from plane geometry to form the chord-line theorem. In this theorem, the concept of two intersecting chords or extended chords is replaced by a single chord-line. (DDR)

Relates one secondary geometry teacher's experiences learning and using the computer program "Geometer's Sketchpad." The article describes the program and provides examples of ways this teacher uses it in combination with more traditional teaching tools. (SM)

Describes activities that use geoboards to explore properties of polygons such as the relationship between a polygon's number of sides and the sum of its interior angles. Describes a generalized method for constructing any Pythagorean triangle. (DDR)

Geometry should be a frequent and familiar part of the elementary school mathematics curriculum. Exercises to help children master basic terminology and visualize shapes and geometric relationships are described. They range from a "shape bag," which teaches simple identification of figures, to more complex activities involving polyominoes and…

Presents the Morris Loe Angle Trisection Approximation Method to introduce students to areas of mathematics where approximations are used when exact answers are difficult or impossible to obtain. Examines the accuracy of the method using the laws of sines and cosines and a BASIC computer program that is provided. (MDH)

Describes origami, the oriental art of paper folding as an activity to teach upper elementary students concepts and skills in geometry involving polygons, angles, measurement, symmetry, and congruence. (PK)

Presents a method that connects the area formulas for triangles, rectangles, parallelograms, and trapezoids by focusing on the relationships between the bases and heights of each figure. Transformations allow figures to be reconceptualized to establish a general concept of area that can be applied to other figures. (MDH)

Offers practical tips on teaching secondary mathematics topics. The ideas are classroom-tested approaches that offer new slants on familiar subjects. The topics discussed include the interpretation of mathematical symbolism in concrete terms, ellipses, and vectors. (PK)

Describes activities in which students perform experiments with physical models that they create. Students develop geometric intuition and build a concrete foundation upon which abstract principles can be built. (DDR)

Durer's method for drawing an ellipse is used to explain why some people think an ellipse is egg shaped and to show how this method can be used to derive the Cartesian form of the ellipse. Historical background and suggestions for further reading are included. (KR)

Examines aspects of Navajo cosmology relevant to understanding Navajo spatial representations. Compares Navajo children's spatial knowledge with Piaget's findings about the development of geometric concepts in Swiss children. Describes classroom activities whereby Navajo children explore the geometry inherent in their cultural and physical…

This paper begins with a description of a set of difficulties in classes where students were given problems which asked them to explore and "make conjectures." After presenting background on debates about discovery learning, changing philosophical conceptualizations of the role of the empirical in mathematics, and innovations involving…

This Comprehensive School Mathematics Program (CSMP) guide is divided into three major parts. The first, the Languages of Strings and Arrows, opens with a suggested lesson order. Major sections cover instructional approaches for: (1) Games with Strings, (2) Necklaces, and (3) The Table Game. A Series of appendices is included. Part 2, Geometry and…