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)

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…

A process for eliminating the xy term in a quadratic equation in two variables is presented. The author feels this process will be within the reach of more high school students than more commonly used methods. (MK)

Derivations of elementary trigonometric identities involving constants (namely, particular values of the sine function) are presented. (MK)

Presents a method to solve differential equations of free damped oscillators, so that general (periodic and aperiodic) solutions can be obtained, solely on the basis of elementary knowledge of differential and integral calculus and avoiding the use of complex functions. (GA)

Specially designed materials were used for teaching trigonometric ratios to 131 ninth- and tenth-grade students, one group using calculators and one not. Results on achievement were mixed. (MP)

Describes a project in which trigonometry and precalculus students cooperate to measure the height of an inaccessible water tower. (MKR)

Illustrates, categorizes, and analyzes typical mathematical errors in algebra and trigonometry made by high school and lower division college students. (16 references) (Author/MKR)

Presents a solution to the problem of finding the probability that a needle would cross a crack in a tile floor when dropped. (MKR)

Discussed are two approaches to determining which regular polygons, either inscribed within or circumscribed about the unit circle, exhibit rational area or rational perimeter. One approach involves applications of abstract theory from a typical modern algebra course, whereas the other approach employs material from a traditional…

Introduced are the basic ideas of interpolation and approximation theory through a combination of theory and exercises written for extramural education at the university level. Topics treated are spline methods, Lagrange interpolation, trigonometric approximation, Fourier series, and polynomial approximation. (MDH)

Introduces handling data as conceived by Euclid, which provides some interesting possibilities for students to investigate fundamental geometrical ideas as well as relating some elementary geometry with elementary trigonometry. (ASK)

Presents problems to find the integrals of logarithmic and inverse trigonometric functions early in the calculus sequence by using the Fundamental Theorem of Calculus and the concept of area, and without the use of integration by parts. (Author/ASK)

Herring in the ocean between Iceland and Norway was one of the largest fish stocks in the world until the fishery crashed in the late 1960s. The catch in 1971 was only 20 thousand metric tons in contrast with the record of 2 million tons in 1966 and the spawning stock declined from 10 million tons to 10 thousand tons in 20 years. After 25 years of…

Several formulae for the inradius of various types of triangles are derived. Properties of the inradius and trigonometric functions of the angles of Pythagorean and Heronian triangles are also presented. The entire presentation is elementary and suitable for classes in geometry, precalculus mathematics and number theory.