TEN LITTLE FINGERS - Arvind Gupta

THREE DIMENSIONAL MODELS1. Pierce a hole in the valve tubejoint-of- two, by poking it atright angles either with a longneedle or else a thorn.2. Insert a third matchstick(slightly sharpenedat the end) in this hole.This is a joint- of - three,or simply a T-joint.TETRAHEDRON3. Take the equilateral triangleand poke holes in its valvetube joints with a thorn.Now insert the three matchstickends of the T-joint in theholes of the triangle.4. This structure is calleda TETRAHEDRON.It has 4 corners, 6edges and 4 distinctsurfaces.5. All its surfaces are equilateraltriangles. Triangles are rigid.So this triangular house is verystrong.6. PENTAGONAL BOX7. In a similar manner two separatetriangles can be joined together usingthree matchsticks to make a PRISM.8. Two separate squares can be joinedwith four matchsticks to make a CUBE.9. Several of these three-dimensionalstructures can be put together to makedifferent kinds of houses and otherconfigurations. You can play with this simplemeccano to create your own models.