Discusses a calculation method to approximate pi. Describes how to get an approximation to the circumscribed and inscribed perimeters of regular polygons of n sides. Presents the computer program and result of the approximation. (YP)

Explores the production of shadows for drawings using the LOGO computer language and Affine Geometry. Explains the methodology of the shadowing and lists the Affine Turtle procedures. Provides for different versions of LOGO. (MVL)

The programing language PROLOG is compared to LOGO in terms of its ability to handle mathematical ideas. This is demonstrated by using PROLOG in solving a geometric theorem and two lemmas. The listings of the computer programs used to solve the problems are included. (KR)

Described is an activity that incorporates a computer, geometry, algebra, trigonometry, and calculus to answer questions about the planet Mars. A possible crescent of Mars is compared to those of Venus and Mercury. (KR)