sábado, 3 de diciembre de 2011

Prismas

Pyramids

pyramid is a structure whose outer surfaces are triangular and converge at a single point. The base of a pyramid can be trilateral, quadrilateral, or any polygon shape, meaning that a pyramid has at least three triangular surfaces (at least fourfaces including the base). The square pyramid, with square base and four triangular outer surfaces, is a common version.A pyramid is a polyhedron whose base is any polygon and whose lateral faces are triangles with a common vertex, which is the apex of the pyramid.





Clasificatión of pyramids

Regular Piramid

dibujo

The base regular pyramid has a regular polygon and its sides equal.

Irregular Piramid

dibujo

The irregular pyramid base is an irregular polygon.

 Convex Pyramid

dibujo

The pyramid base is convex a convex polygon.

Concave Pyramid

dibujo

The pyramid base convex polygon is concave.

Straight Pyramid

dibujo
                                                                                                                                                       In all right pyramid with sides alturacae isosceles triangles and the midpoint of the base.

Oblique Pyramid

dibujo

In the pyramid oblique one of its sides is an isosceles triangle.

Clasificatión of pyramides as it base

Triangular Pyramid

 triangular

Its base is a triangle

Square Pyramid

 cuadrangular

Its base is a Square

Pentagonal Pyramid

 pentagonal

Its base is a pentagon

Hexagonal Pyramid

 hexagonal

Its base is a hexagon



Calculation of the side of a pyramid apothem

apotema lateral de la pirámide


We calculate the apothem of the pyramid side, knowing the height and apothem of the base, using the Pythagorean theorem in the shaded triangle:
apotema lateral de la pirámide
apotema lateral de la pirámide

Calculation of the lateral edge of a pyramid

arista lateral de la pirámide


We calculated the lateral edge of the pyramid, knowing the height and base radius or radius of the circumscribed circle, using the Pythagorean theorem in the shaded triangle:
apotema lateral de la pirámide
apotema lateral de la pirámide

Lateral area of a Pyramid

Área lateral de una pirámidea
área y  volumen

Área of a pyrámid

Área de una pirámide

Volume  of a pyramid

Volumen de una pirámide




Prisms

The initial and final positions of the polygon are called bases and two polygons areequal. That same polygon is repeated in all planes parallel to the bases.
The distance between bases is called height.
The segments traversed by the lateral edges are called vertices, that determines the lateral movement.

Polyhedrons

Polyhedrons
Polyhedrons: Son cuerpos geométricos cuyas caras son planas (polígonos) y encierran un volumen.
polyedrons can be two types:
          Prismahave two bases and lateral faces are parallelograms. In the drawing are identified elements that compose it.
          Pyrámidhave a base and its sides are triangles. In the drawing are identified elements thatcompose it.

For naming prisms or pyramids are placed the name of the database, so we have "hexagonal prism" (base hexagon) and "octagonal pyramid" (base octagon).