The Compendium Geometry is an eBook providing facts, formulas and explanations about geometry. 
Home Analytic Geometry 3D Solids Platonic Solids Tetrahedron  
See also: Pyramid, Platonic Solids  Regular Polyhedra  
Search the VIAS Library  Index  
TetrahedronA (regular) tetrahedron is a polyhedron composed of four equilateral triangular faces, three of which meet at each vertex. It is one of the Platonic solids. The tetrahedron has 7 axes of symmetry: 4 C_{3} (axes connecting vertices with the centers of the opposite faces) and 3 C_{2} (the axes connecting the midpoints of opposite sides). The height h of the tetrahedron is defined by h = a/ The volume V of the tetrahedron is given byV = A_{b}h/3 = a^{3}/12 with A_{b} being the area of the base triangle. The surface area S of the tetrahedron isS = a^{2} The radii of the circumscribed (r_{c}) and inscribed (r_{i}) spheres arer_{c} = a/4 and r_{i} = a/12, respectively.


Home Analytic Geometry 3D Solids Platonic Solids Tetrahedron 