Monday, September 3, 2012

Triangular Pyramid Vertices

Introduction

Triangular pyramid is one type of three dimensional shapes. It has four vertices. Three vertices are in the base and one vertex is on top of the pyramid. Vertices are nothing but the corner points of the pyramid. The shape of the triangular pyramid is shown in below. In the figure A, A', B, B', C, C'  are the vertices. Let us see how to calculate the volume and surface area of the triangular pyramid.

Formula Used to Find Volume and Surface Area of Triangular Pyramid:
Surface area of the triangular pyramid (SA) = A + `(p * l) / (2)` square units

A – Base area

p – Perimeter of base

l – Slant height



Volume of triangular pyramid (V) = `1/3` A h cubic units

A – Area of the base

h – Height of the pyramid

I am planning to write more post on how to factor polynomial, solve the system of linear equations. Keep checking my blog.

Vertices of Triangular Pyramid– Example Problems:

1. The triangular pyramid has the vertices A (0, 0), B (18, 0), slant height (l) = 15 units, height (h) = 12 units. Find the volume and surface area of the triangular pyramid.

Solution:

Given:

A (0, 0), B (18, 0)

Slant height (l) = 15

Height (h) = 12

Length between two vertices (a) =` sqrt ((y_2- y_1)^ 2 + (x_2- x_1)^2)`

= `sqrt((0-0)^2+(18-0)^2)`

= `sqrt(324)`

a = 18 units

Base area (A):

Base area of the triangle (A) = a2 x `sqrt (3) / 4` square units

= 182 x 0.433

= 324 x 0.433

Base area of the triangle (A) = 140.292 square units

Perimeter of the base (P):

Perimeter of the base (p) = 3 a units

= 3 x 18

= 54 units

Surface area (SA):

Surface area of the triangular pyramid (SA) = A + `(p * l) / 2` square units



= 140.292 + `(54 X 15) / 2`

= 140.292 + 405

Surface area of the triangular pyramid (SA)    = 545.292 square units

Volume (V):

Volume of triangular pyramid (V) = `1/3` A h cubic units

= `1/3` x 140.292 x 12

= `1/3` x 1683.504

Volume of triangular pyramid (V) = 561.168 cubic units

2. The triangular pyramid has the vertices A (0, 0), B (10, 0), slant height (l) = 7.8 units, height (h) = 6 units. Find the volume and surface area of the triangular pyramid.

Solution:

Given:

A (0, 0), B (10, 0)

Slant height (l) = 7.8

Height (h) = 6

Length between two vertices (a) = `sqrt ((y_2- y_1)^2 + (x_2-x1)^2)`

= `sqrt((0-0)^2+(10-0)^2)`

= `sqrt(100)`

a = 10 units

Base area (A):

Base area of the triangle (A) = a2 x `sqrt (3) / 4 ` square units

= 102 x 0.433

= 100 x 0.433

Base area of the triangle (A) = 43.3 square units

Perimeter of the base (P):

Perimeter of the base (p) = 3 a units

= 3 x 10

= 30 units

Surface area (SA):

Surface area of the triangular pyramid (SA) = A + `(p * l) / 2` square units



= 43.3 + `(30 X 7.8) / 2`

= 43.3 + 117

Surface area of the triangular pyramid (SA)    = 160.3 square units

Volume (V):

Volume of triangular pyramid (V) = `1/3` A h cubic units

= `1/3` x 43.3 x 6

= `1/3` x 259.8

Volume of triangular pyramid (V) = 86.6 cubic units

My Previous Blog :- http://advancemath.blogspot.in/2012/09/vertical-line-equation.html

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