Tetrahedron in stereometry is called the polyhedron which consists of four triangular sides. The tetrahedron has 6 edges and on 4 sides and tops. If at a tetrahedron all sides are the correct triangles, then and the tetrahedron is called correct. The area of a full surface of any polyhedron including a tetrahedron it is possible to calculate, knowing the areas of its sides.
Instruction
1. To find the area of a full surface of a tetrahedron, it is necessary to calculate the area of the triangle making its side. If the triangle equilateral, then its area ravnas = √3 * 4/a² where an is a tetrahedron edge, then the surface area of a tetrahedron is on formules = √3 * a².
2. In case the tetrahedron is rectangular, i.e. all flat corners at one of its tops are straight lines, then the areas of three of its sides which are rectangular triangles can be calculated on formules = a * b * 1/2, S = a * with * 1/2, S = b * with * 1/2, the area of the third side can be calculated on one of the general formulas for triangles, for example on a formula GeronaS = √ (p * (p - d) * (p - e) * (p - f)) where p = (d + e + f)/2 – poluperimetr a triangle.
3. Generally, the area of any tetrahedron can be calculated, using Heron's formula for calculation of the areas of each its side.