In some secondary mathematics curricula, there is a topic called Stereometry that deals with investigating the position and finding the intersection, angle, and distance of lines and planes defined within a prism or pyramid. Coordinate system is not used. The metric tasks are solved using Pythagoras' theorem, trigonometric functions, and sine and…

Archimedes viewed the method of centroids as a valuable tool for intuitive discoveries. This article presents several uses of this technique and discusses how the method of centroids could be used in secondary schools. (Author/MK)

This article is an attempt to convince the reader that transformational geometry (motion geometry) can be dealt with in a significant manner for students in the junior high school. (Author)

PRESENTED IS A FUSED COURSE IN PLANE, SOLID, AND COORDINATE GEOMETRY. ELEMENTARY SET THEORY, LOGIC, AND THE PRINCIPLE OF SEPARATION PROVIDE UNIFYING THREADS THROUGHOUT THE TEXT. THE TWO CURRICULUM GUIDES HAVE BEEN PREPARED FOR USE WITH TWO DIFFERENT TEXTS. EITHER CURRICULUM GUIDE MAY BE USED DEPENDING UPON THE CHOICE OF THE TEACHER AND THE NEEDS…

This article "opens up" the study of the relationship between quadrilaterals and circles to two sets of quadrilaterals--those that can be drawn either inside (cyclic) or outside (tangential) a circle (or both). Of course, "all" triangles are both cyclic and tangential. Or, to use the traditional Euclidean language for triangles, a unique…

Shows a way in which algebra and geometry can be used together to find the lengths and areas of spirals. This method develops better understanding of shapes, similarity, and mathematical connections in students. Discusses spirals embedded in triangles and squares, the Pythagorean theorem, and the area of regular polygons. (MKR)

Explores areas of polygons by comparing polygon area to the area of the associated midpoint polygon, formed by joining the midpoints of consecutive sides. Considers triangles, quadrilaterals, pentagons, and regular polygons using paper folding, drawings on graph paper, and plexiglass MIRA constructions. (Contains 12 references.) (MKR)

This is one of a series of geometry modules developed for use by secondary students in a laboratory setting. The authors of this sequence of modules have chosen not to cover the initial basic postulates and theorems since they can be found in nearly every geometry text. Instead, a list of necessary postulates and their consequences is included. It…

Mnemonic devices to aid in the teaching of perimeter and circumference are suggested. (MK)

This is one of a series of geometry modules developed for use by secondary students in a laboratory setting. This module, intended to present a treatment of congruent triangles which is not totally axiomatic, contains six sections: (1) Draw vs. Construct; (2) Triangle Construction; (3) Arguing for Congruence; (4) Parallel Line Construction; (5)…

This is the teacher's edition of a text for the first year of a two-year high school geometry course. The course bases plane and solid geometry and trigonometry on the fact that the translations of a Euclidean space constitute a vector space which has an inner product. Volume 1 deals largely with affine geometry, and the notion of dimension is…

This is one of a series of geometry modules developed for use by secondary students in a laboratory setting. This module was conceived as an alternative approach to the usual practice of giving Euclid's parallel postulate and then mentioning that alternate postulates would lead to an alternate geometry or geometries. Instead, the student is led…

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)

This is one of a series of geometry modules developed for use by secondary students in a laboratory setting. The thrust of this module is to introduce the student to transformations by having the student physically transform sets of points. Heavy use of manipulatives is made to aid the student in the transforming activity. Individual sections…

This is the teacher's edition of a text for the second year of a two-year high school geometry course. The course bases plane and solid geometry and trigonometry on the fact that the translations of a Euclidean space constitute a vector space which has an inner product. Congruence is a geometric topic reserved for Volume 2. Volume 2 opens with an…