Presented are some of the special properties possessed by a triangle in which the measure of one of its three angles is one-half the measure of another of these angles. The author names such a triangle a vux triangle. (RP)

Presented is the official mathematics program for all seventh grade students in Belgium, beginning September, 1968. Methods of instruction are suggested for the several curriculum content areas -- sets, relations, integers, and geometry. (RP)

Describes the college-level course offered at the State University of New York, which combines plane geometry and plane trigonometry. Explains lesson sequences and sample exercises to show how the course develops all of the major principles of geometry and trigonometry using three basic constructions: perpendicularity, angle congruency, and angle…

The material attempts to find the maximum number of non-congruent figures that can be generated from a nine-pin geoboard, and considers the maximum number of figures possible on boards of any size. The exploration starts by grouping sets of pin patterns into groups of equivalent classes. (MP)

Four problems are given and discussed involving reflection about a line or the reflection properties of conic sections. Solutions are given. (MP)

An investigation is reported of differences in boys and girls in three grade levels of the identification and construction of embedded and overlapping figures and the effect of instruction on identification. The only significant differences found were across the grade levels in construction. (MK)

Topics discussed by the renowned geometer include: his early interest in mathematics, the nature of geometry, geometry education, and the future of geometry. (MK)

Activities to be used before teaching the Pythagorean Theorem are described. Sample worksheets are provided. (MK)

A discussion is given of the nature of spatial ability and a rationale is provided for use of spatial activities such as tiling, tangrams, and polyominoes. (MP)

An activity unit is described that helps children recognize the inside and outside of closed curves. (MP)

Sixty-three high school geometry teachers and college mathematics educators rated each of 35 geometry objectives on a scale from very important to unimportant. Results of these ratings are reported and discussed. (DT)