Mechanical Linkages and Deductive Geometry

Mechanical linkages – sets of hinged rods – form the basis of many everyday objects such as ironing tables, car jacks, elevated work platforms and folding umbrellas. Many of these objects incorporate geometry very appropriate to the middle years including isosceles triangles, rhombuses and parallelograms. They offer rich potential for investigating geometry, with working models or real-life examples, and then with dynamic geometry software. Students’ deductive reasoning is developed when working with and exploring the models (tactile and virtual). There are four units designed for each of Years 7 to 10.

Students will need computers or tablets to run the prepared Geogebra files. Geogebra can be freely downloaded from Students can construct linkages using ‘Geostrips’, corflute or card and paper fasteners.