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Finding Area and Volume

Date: 04/12/2001 at 19:20:06
From: Brandi
Subject: Finding the Volume of Triangles

How do I know what to divide the B (base) by? For example, I Have 7.5 
for the base and 3 for the height. Do I multiply it by 1/2 or 1/3?

Date: 04/13/2001 at 12:39:51
From: Doctor Peterson
Subject: Re: Finding the Volume of Triangles

Hi, Brandi.

The formula for the area (not volume!) of a triangle, which you can 
find in our Dr. Math FAQ (see Formulas), is:

     A = 1/2 b h

This means you multiply the base length by the height, and divide 
by 2.

The formula for volume of a PYRAMID is similar, but different:

     V = 1/3 B h

Here you multiply the AREA of the base by the height and divide by 3. 

Just remember, for a two-dimensional thing that comes to a point, I 
divide by 2; for a three-dimensional thing that comes to a point, I 
divide by 3.

- Doctor Peterson, The Math Forum   
Associated Topics:
High School Geometry
High School Polyhedra
High School Triangles and Other Polygons
Middle School Geometry
Middle School Polyhedra
Middle School Triangles and Other Polygons

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