Question

The top of the Washington Monument is a triangular pyramid with a triangle base. Each triangular face is 58 feet tall and 34 feet wide and covered with white marble. About how many square feet of marble cover the faces of the pyramid?

Answer 1

`3,944ft^(2)` of marble is needed.

Explanation:

The picture below represents the top of the Washington Monument, with 4 triangles, one on the base and the other 3 forming the monument.

First of all whe have to find the area of one pyramid:

`A=(height*width)/(2)`

Replacing the values, we have:

`A=(58ft*34ft)/(2)`

`A=986ft^(2)`

As we have 4 triangles forming the top of the Monument, we have to multiply by 4 to find the quantity of marble to use:

Quantity of marble=Area of each triangle * quantity of triangles

Quantity of marble=
`986ft^(2)*4`

Quantity of marble=
`3,944ft^(2)`