GeoGebra is the most well-known Dynamic Geometry Application (DGA) in the world. Many researchers are interested in GeoGebra as a tool to make interactive mathematics resources. Here we focus on a snapping function in GeoGebra, which is a kind of general feature of DGA: the mouse cursor is attracted to a specific position or a specific object and…

The use of a ruler with two parallel Straight edges as a tool in geometric constructions is presented, based on ideas that are fairly standard in high school geometry courses. The constructions are seen as potential challenges that provide opportunities for inventiveness by students. (MP)

Geometric construction problems are recommended as sources of stimulating exercises for mathematics classes. (MP)

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)

Presented is a method for finding two triangles that have five pairs of congruent parts, yet fail to be congruent. The solution is thought to involve some creative insights that should challenge both the teacher and students to recall and analyze all the congruence axioms and theorems. (MP)

Presents activities to teach the formula for the area of a rectangle that require students to determine the cost of refurbishing their school's tennis courts. Students collect their own data, organize information, and make decisions individually and as a group to solve the problem. Worksheets are provided. (MDH)

Presents a series of four worksheets to develop students' perception of spatial relationships. The tasks require students to use cubes to build models and describe the models by representing the front, right, and top views on grid paper. Provides reproducible worksheets. (MDH)