Wednesday, June 12, 2013

Volume of a pyramid

Volume of a pyramid

Volume of a pyramid video

What is a pyramid? A pyramid is a three dimensional figure that has a base and an apex which you can think of as a point.

The formula for volume equals 1/3 * base * height

The base area will depend on the shape of the base.

For example if the shape of the base is a square you would just multiple length times width

If the shape is a triangle you would take ½ base * height to get the base and then multiply this by the height of the triangle.

Check here for a list of base area formulas.

Problem 1. Find the volume of a pyramid with a square base that has a side of 4 units and a height of 5 units.

 

Step 1. Find the base area 4 * 4 = 16 units

Step 2. Multiply base area times height = 16* 5 = 80 units

Step 3. Multiply this by 1/3 ( remember the formula is 1/3 * base * height = 1/3*80 = 26.6 units cubed

Problem 2. Find the volume of a pyramid with a triangle base with a base of 6 units and a height base of 8 units and a pyramid height of 7 units

 

 

 

 

Step 1. Find the base area using the formula ½ base * height

Step 2. ½ * 6 * 8 = 24 units

Step 3. Find the volume using 1/3 * base * height3

Step 4. 1/3 * 24 * 7 = 8*7

Step 5. 8*7 = 56 units cubed