2Piece Pyramid, 4piece Pyramid
Tasks


MathsThe 2piece pyramid is made from two identical pieces. Since a tetrahedron only has triangular faces, the square faces of the 2piece pyramid have to vanish. This can be achieved by putting the square faces together. In other words, the square is hidden inside the tetrahedron. In fact, it is a crosssection of the tetrahedron. The four edges of the square lie on each of the four faces of the tetrahedron. 

HistoryThe tetrahedron is called a Platonic solid. These solids have identical regular polygon faces, (such as triangles, squares and pentagons), and the same number of faces at each corner. There are only five Platonic solids, the tetrahedron, cube, octahedron, icosahedron and dodecahedron. They are named after the ancient Greek philosopher Plato, who associated these solids with the classical elements of fire, earth, air, water and a fifth element called “quintessence”. 

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ApplicationsThe tetrahedron shape can be often found in chemistry when looking at the shape of molecules. For example, methane is a central carbon atom surrounded by four hydrogen atoms. The hydrogen atoms repel each other and want to be as far apart as possible, so form a tetrahedron shape.An irregular volume in space can be approximated by an irregular triangulated surface, and irregular tetrahedral volume elements. This has applications in aerodynamics and engineering. 

Maths at HomeMake the 2piece puzzle at home by printing this net onto thin card. Cut out the two shapes and glue the tabs to make the 2pieces. 