Problems in space geometry are discussed. Studying the equilateral triangle through its involvement in the solution of applied problems is advocated. (SD)

A game, similar to bingo is described, in which students match names, symbols, and figures. (SD)

Activities in which students make and prove conjectures and devise their own geometric axiom systems are discussed. (SD)

Examples of activities involving geometric construction are suggested for discovery-oriented instruction. (SD)

A particular shot on a pool table is analyzed using the concept of similar triangles, to introduce the equivalence of the "incident-reflection" principle and the "minimum-distance" principle. (CR)

Rational points in the plane were defined as points having both coordinated rational. Students solved several problems linking rational points with lines, circles, and other geometric figures. (SD)

Results of operations on the Pythagorean formula are interpreted pictorially to yield interesting art forms. (MP)

Pick's Theorem, a statement of the relationship between the area of a polygonal region on a lattice and its interior and boundary lattice points, is familiar to those whose students have participated in activities and discovery lessons using the geoboard. The proof presented, although rather long, is well within the grasp of the average geometry…

Construction of a series of 13 nested, regular tetrahedrons from 12 square sheets of paper without using geometric instruments, scissors, or glue is described. (MN)

The authors derive distance formulas in two-and-three-dimensional coordinate geometry utilizing the concept of similar triangles and the Pythagorean theorem. (MN)

Geometry and a hand-held calculator are used to find a value of pi accurate to five decimal places. (CP)

This article provides a manipulative demonstration of the relationship between the squares on the sides of a right triangle. Materials are listed and directions are given for the student. Illustrations are included. (Author/MA)

This article examines the Pythagorean Theorem from a geometric point of view by suggesting some natural extensions of the theorem. The use of a more general theorem to prove a difficult one is suggested, where possible. The article includes figures and proofs. (Author/MA)