Danny is building a pyramid modeled after one of the Great Pyramids of Giza in Egypt. The Great Pyramid has a height of 480 feet and a square base with a side measuring 755 feet. Danny wants to build his pyramid with dimensions that are [tex]$\frac{1}{80}$[/tex] those of the Great Pyramid.

What will be the approximate volume of Danny's pyramid?

A. [tex]$18.9 \, \text{ft}^3$[/tex]
B. [tex]$1510 \, \text{ft}^3$[/tex]
C. [tex]$178.1 \, \text{ft}^3$[/tex]
D. [tex]$534.4 \, \text{ft}^3$[/tex]



Answer :

To find the volume of Danny's pyramid, we need to perform the following steps:

1. Determine the scaled dimensions of Danny's pyramid, given that the scale factor is [tex]\( \frac{1}{80} \)[/tex] of the original Great Pyramid.

2. Calculate the base area of Danny's pyramid.

3. Calculate the volume of Danny's pyramid using the formula for the volume of a pyramid.

### Step-by-Step Solution

1. Determine the scaled dimensions

- The original height of the Great Pyramid is 480 feet. Scaling this by [tex]\( \frac{1}{80} \)[/tex]:
[tex]\[ \text{Height of Danny's pyramid} = 480 \times \frac{1}{80} = 6 \text{ feet} \][/tex]

- The original side length of the base is 755 feet. Scaling this by [tex]\( \frac{1}{80} \)[/tex]:
[tex]\[ \text{Side length of the base} = 755 \times \frac{1}{80} = 9.4375 \text{ feet} \][/tex]

2. Calculate the base area

The base area of a pyramid with a square base is given by the side length squared:
[tex]\[ \text{Base area} = 9.4375^2 = 89.06640625 \text{ square feet} \][/tex]

3. Calculate the volume

The volume [tex]\( V \)[/tex] of a pyramid is given by the formula:
[tex]\[ V = \frac{1}{3} \times \text{Base area} \times \text{Height} \][/tex]

Plugging in the values we calculated:
[tex]\[ V = \frac{1}{3} \times 89.06640625 \times 6 = 178.1328125 \text{ cubic feet} \][/tex]

### Conclusion

The approximate volume of Danny's pyramid is [tex]\( 178.1 \, \text{cubic feet} \)[/tex].

Thus, the correct answer is:
[tex]\[ 178.1 \, ft^3 \][/tex]

Hence, the appropriate choice from the given options is:
[tex]\[ 178.1 \, ft^3 \][/tex]