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

The activities are designed to have students manipulate physical models of geometric figures, engage in spatial visualization and observe relationships between triangles and parallelograms and between triangles and rectangles. Worksheets designed for duplication are included in the materials and an answer key is provided. (MP)

This paper is the second part of a study of plane transformations using a complex setting. The first part was devoted to homotheties and translations, now attention is turned towards plane isometries. The group theoretic properties of plane isometries are easy to derive and images of classical geometrical objects by these transformations are…

One of the most interesting episodes in the saga of angle trisection was Archimedes' discovery that he could trisect an angle if he could make two marks on his straightedge. This note gives a method of trisection without marks; of course, one does have to "cheat" a little.

The problem of angle trisection continues to fascinate people even though it has long been known that it can't be done with straightedge and compass alone. However, for practical purposes, a good iterative procedure can get you as close as you want. In this note, we present such a procedure. Using only straightedge and compass, our procedure…

Research has shown that affordances of computers may be exploited in the design of mathematical tasks so as to provide interesting and challenging activities. At the same time, opportunities for learning mathematics may be constrained if the design of the task is not appropriate. A tool which allows teachers, researchers and task designers to…

A GUIDE FOR A 1-YEAR COURSE IN DIFFERENTIAL AND INTEGRAL CALCULUS PREREQUISITED KNOWLEDGE IN ALGEBRA, ANALYTIC TRIGONOMETRY, AND ELEMENTARY ANALYSIS. EACH ASSIGNMENT CONTAINED BOTH NEW AND REVIEW WORK TO REINFORCE THE NEW WORK. THERE WERE ELEVEN UNITS OF STUDY USING THE FOLLOWING FOUR BOOKS--"CALCULUS AND ANALYTIC GEOMETRY, THIRD…

The third in a series of four articles, this is concerned with establishing the main properties of the general linear transformation of the plane, equations of lines, area, and change of axes. For earlier articles, see MT number 57, Winter 1971, pp. 14-19 and MT number 58, Spring 1972, pp. 49-55. (DT)

A discussion of the so-called rose curves defined by simple trigonometric functions in polar coordinates. (MM)

This article presents some easily stated but unsolved geometric problems. The three sections are entitled: Housemoving, Manholes and Fermi Surfaces" (convex figures of constant width), Angels, Pollen Grains and Misanthropes" (packing problems), and The Four-Color Conjecture and Organic Chemistry." (MM)

Conditions for congruency of triangles are investigated. (DT)