Presents 10 creative, informal, intuitive geometry activities that stress higher-order thinking. (MKR)

Describes the use of formal writing and speaking in upper level geometry and analysis courses. Includes student journals, students reviewing written proofs with a student writing associate, and simulated conferences. Includes a 16-item list of possible topics. (Author/MKR)

Proposes that the writing of proofs in geometry class can be a vehicle for attaining the goals of problem solving, reasoning, and communication in the mathematics classroom. Presents a student-teacher dialogue illustrating this process. (11 references) (MKR)

A preservice teacher education course involving the applications for a computer within the mathematics classroom is described in terms of its evolution from a workshop to a regular curricular offering. Included are samples of computer experiments which suggest computer teaching activities for the prospective teacher lacking in field experience.…

This article offers a diversity of approaches for the conceptual development of the summation of the interior angles of polygons. Included are activities that suggest various possibilities for a study of angle sums that build upon an awareness of geometric transformations, particularly dissections and combinations. (JJK)

Various modes of reflection are classified and practical examples of devices, such as cat's eyes, are discussed. Typical light rays are traced through several systems, providing exercises with varying degrees of difficulty. Corner-cube retroreflectors, glass spheres, reflecting luminaries, light concentrators, parabolic reflectors, and off-set and…

Discusses activities to teach Cartesian graphing to young children in a conceptual way. Activities are organized around the concepts of finding one's way around in a plane and using the plane to represent variables in two dimensions by graphing equations in the usual way. (25 references) (MKR)

Presented is an activity designed to help middle school students in their understanding of definitions in geometry. Five definitions involving complex quadrilaterals are discussed. Procedures and expectations for the activity are described. (CW)

Utilized is the technique of expanding circles to explore the truth of the statement that, if the sums of the lengths of the opposite sides of a quadrilateral are equal, then a circle can be inscribed within that quadrilateral. This statement is the converse of a well-known geometric theorem. (JJK)

Examines correct and incorrect student-developed criteria for parallelograms. (MKR)

Introduces a few examples of Mangbetu designs and examines their underlying structure. Describes Mangbetu design and analyzes its geometric features. (ASK)

Presents an activity using dynamic-geometry system software to create an environment in which all students can explore and extend the locus definition of conics. (ASK)

Focuses on teaching in China, concentrating on two particular aspects of teaching: teaching students to prove in geometry and the details of what teachers do in classrooms. (ASK)

Opens with the theoretical construct of figural concepts. Argues that geometrical figures are characterized by both conceptual and sensorial properties. Investigates the effects of interaction between conceptual and figural components. Contains 19 references. (DDR)

Discusses the importance of using children's previous experiences with geometric figures to build foundations for developing geometric thinking. Describes how children's play with unit blocks can be structured to give them experiences with geometric concepts. Contains 12 references. (ASK)