The author uses Stella the Spider as the main character in a number of three-dimensional geometry problems. Eight of these problems are discussed, with solutions. (MNS)

Describes a model for geometrical probability. Presents two examples of basic theories of probability using geometrical probability. Provides three problems using the described theorem. (YP)

Discusses geometric construction problems. Presents four ways to construct a regular octagon using different conditions. Provides drawings showing the constructions. (YP)

Using the two posters in this article, students are to search for patterns as a way of counting different types of squares and cubes obtained from a larger square or cube that is printed on the outside edge or surface. (MP)

To help mathematics teachers introduce and reinforce concepts and processes by using relevant problems, several such problems are presented and discussed. (MNS)

Five basic skill areas needing more attention in standard high school geometry are discussed. Levels of student mental development in geometry and a need for less emphasis on formal proofs are reviewed. (MP)

Presents 14 distinct methods to determine the sine of the angle formed by the line segments joining one vertex of a square to the midpoints of the nonadjacent sides. Nine methods were developed by mathematics club participants preparing for mathematics competitions and the remaining five by faculty members. (MDH)

Given are activities involving the use of triangles and triangle paper, in the form of problems that require searching for different possibilities to fit a given condition. (MP)

Five sets of activities for students are included in this document. Each is designed for use in secondary school mathematics instruction. Topics include: (1) "5-Con Triangles"; (2) "Striking Sequences"; (3) "Invariants"; (4) "On the Ball," (a geometry lesson); and (5) "Coloring Maps." These topics focus on geometric and statistical concepts. Each…

From 1984 through 1988, the authors worked with teachers using an inquiry approach to teach high school geometry courses with the aid of the "Geometric Supposers." Problems are a critical component of the approach because they focus attention and energy and guide students in the application, integration, and extension of knowledge.…