The pyramid represents a polyhedron which sides are the triangles having the general top. Calculation of a side edge is studied at school, in practice often it is necessary to remember an almost forgotten formula.
Instruction
1. By the form the bases the pyramid can be triangular, quadrangular, etc. The triangular pyramid is called also a tetrahedron. In a tetrahedron any side can be taken for the basis.
2. The pyramid is regular, rectangular, truncated, etc. Correct the pyramid is called in case its basis is the regular polygon. Then the center of a pyramid is projected on the center of a polygon, and side edges of a pyramid are equal. In such pyramid the side sides are identical isosceles triangles.
3. The rectangular pyramid is called when one of her edges is perpendicular to the basis. Height of such pyramid is this edge. At the heart of calculations of values of height of a rectangular pyramid, lengths of her side edges the known Pythagorean theorem lies all.
4. For calculation of an edge of a regular pyramid it is necessary to carry out its height from pyramid top on the basis. Further to consider a required edge as a leg in a rectangular triangle, also using Pythagorean theorem.
5. The side edge in this case is calculated on a formula b= √ by h2 + (a2 • sin (180 °) 2. It is a square root from the sum of squares of two parties of a rectangular triangle. One party is h pyramid height, other party – the piece connecting the center of the basis of a regular pyramid to top of this basis. In this case and – the party of a regular polygon of the basis, n - number of its parties.