Clements, Douglas H., Teaching Children Mathematics
The Geometry Inventor is a software package with activities that teachers can use throughout middle school and secondary school geometry curricula. It is intended for exploration and discovery and offers several tools to construct geometric figures. Those figures can then be easily manipulated on the screen while still maintaining certain defining properties. The software also includes dynamic measuring tools for length, angle measure, and area. The Geometry Inventor follows in the footsteps of the early Geometric Supposer series and The Geometer's Sketchpad. All three programs offer geometric construction and measurement; all three also are designed to support reform movements in mathematics education.
The program allows students to construct points, segments, circles, parallels, perpendiculars, angle bisectors, and extensions of line segments. Students can label various types of points, for example, intersections. They can also measure angles and lengths, compute perimeters and areas, divide segments into sections of equal length, and rescale drawings. They can perform arithmetic combinations on these measures, such as computing the sum of two angles, the square of the length of a segment, or the ratio of two areas. Significantly, all these operations can be conducted simply and accurately and are automatically recorded on the screen. Finally, and perhaps most important, the program records the sequence of constructions and can automatically perform it again, with variations. Thus, students can explore the generality of the consequences of constructions. The process of moving from specific to general cases is crucial in middle and high school mathematics and relates well to the process of understanding variables in algebra. …