Question

A sign made od soild wood is in the shape of a pyramid. The base is a triangle with a base of 6 feet and a height of 4 feet. The height of the sign is 7 feet. The wood costs $3 per cubic foot. What is the cost of the sign?A. $28B. $56C. $84D. $168

Answer 1

The volume of a pyramid can be calculated using the next formula

`A=(1)/(3)(B* h)`

where B is the area of the base

`B=\frac{\text{base x heigth}}{2}=(6*4)/(2)=(24)/(2)=12ft^2`
`h=7`

we substitute the values

`V=(1)/(3)(12\cdot7)=28ft^3`

then we will calculate the cost

1 cubic foot--- $3

28 cubic feet --- x

`x=28\cdot3=84`

the cost of the sign is $84