Concepts and formulae of Pyramid and Tetrahedron for SSC CGL

Detailed Concepts and formulae of Pyramid and tetrahedron for SSC CGL Exam


A Pyramid is a three-dimensional polyhedron of which one face is a polygon of any number of sides, and the other faces are triangles with a common vertex.

A pyramid with an n-sided base will have n + 1 vertices, n + 1 faces, and 2n edges.














Right Pyramid: A right pyramid has its apex directly above the centroid of its base.

Regular Pyramid: A regular pyramid has a regular polygon base.

Generic Formulas: 


Volume Of Pyramid 1/3× Base Area × Height

Surface Area Of pyramid = 1/2 × Perimeter of base  × Slant Length


(only when all side faces are the same)

Surface Area = Base Area + Lateral Area
(When side faces are different)


Regular Right Pyramid with Square base (pentahedron):


Square pyramid is a pyramid having a Square base and the other faces are all triangles.

There are (4+1) faces, 5 vertices and 8 edges in a pentahedron.







Formulas: 

                                         
                                             
     V = 1/3 Bh 



where, e is the edge length, s is the slant height, h is the height, A is the Surface area, AL is the lateral Surface area, B is the area of the square base and a is the length of a side of the base.

   


Regular Right Pyramid with Triangular base (Tetrahedron):


triangular pyramid is a pyramid having a triangular base. 

The tetrahedron is a triangular pyramid having congruent equilateral triangles for each of its faces.

There are 4 faces, 4 vertices and 6 edges in a tetrahedron.



    h = (√2)/(√3) * (Side)

    AL = (3√3)/4 * (Side)2



    A = (4√3)/4 * (Side)2

    V = (√2)/12 * (Side)3                (Since V= 1/3 Bh )



where, e is the edge length, s is the slant height, h is the height, AL is the lateral Surface area, A is the Surface area, V is Volume, B is the area of the base and a is the length of a side of the base.



|| Prism, || Cone, || Cylinder,  || Sphere,Hemispheres, || 
|| Parallelepiped,  || Pyramid ||







Concepts and formulae of Pyramid and Tetrahedron for SSC CGL Concepts and formulae of Pyramid and Tetrahedron for SSC CGL Reviewed by Admin on 1:54:00 PM Rating: 5
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