A pyramid has a square base with side length 5. The height of the pyramid is [tex]\frac{2}{3}[/tex] that of its side. What is the expression for the volume of the pyramid?

A. [tex]V=2 s^2[/tex]

B. [tex]V=25^3[/tex]

C. [tex]V=\frac{2}{3} s^2[/tex]

D. [tex]V=\frac{2}{5}[/tex]

E. [tex]V=\frac{1}{3} s^3[/tex]

(Note: The correct volume expression should be [tex]V=\frac{1}{3} \text{base area} \times \text{height}[/tex], and with the given side length and height, the correct option needs to be calculated.)



Answer :

To find the volume of a pyramid with a square base, let's go through the solution step by step.

1. Identify the side length of the base:
The side length of the square base, [tex]\( s \)[/tex], is given as 5.

2. Calculate the height of the pyramid:
The height of the pyramid is [tex]\(\frac{2}{3}\)[/tex] that of the side length:
[tex]\[ \text{Height} = \frac{2}{3} \times 5 = \frac{10}{3} \][/tex]

3. Find the area of the base:
Since the base is a square with side length [tex]\( s = 5 \)[/tex]:
[tex]\[ \text{Base Area} = s^2 = 5^2 = 25 \][/tex]

4. Use the formula for the volume of a pyramid:
The volume [tex]\( V \)[/tex] of a pyramid is given by [tex]\(\frac{1}{3} \times \text{Base Area} \times \text{Height}\)[/tex]:
[tex]\[ V = \frac{1}{3} \times 25 \times \frac{10}{3} \][/tex]

5. Simplify the expression:
[tex]\[ V = \frac{1}{3} \times 25 \times \frac{10}{3} = \frac{25 \times 10}{9} = \frac{250}{9} \approx 27.77777777777777 \][/tex]

Given this true numerical result, identify the correct expression from the options provided:

- Option A: [tex]\(V = 2 s^2\)[/tex]
- Option B: [tex]\(V = 25^3\)[/tex]
- Option C: [tex]\(V = \frac{2}{3} s^2\)[/tex]
- Option D: [tex]\(V = \frac{2}{5}\)[/tex]
- Option E: [tex]\(V = \frac{1}{3} s^3\)[/tex]

The correct mathematical expression for the volume, given [tex]\( s = 5 \)[/tex], aligns with:

[tex]\[ V = \frac{1}{3} s^3 \][/tex]

This corresponds to Option E, [tex]\( V = \frac{1}{3} s^3 \)[/tex]. Thus, the expression that represents the volume of the pyramid is:

E. [tex]\( V = \frac{1}{3} s^3 \)[/tex]