Six identical square pyramids can fill the same volume as a cube with the same base. If the height of the cube is [tex]$h$[/tex] units, what is true about the height of each pyramid?

A. The height of each pyramid is [tex]\frac{1}{2} h[/tex] units.
B. The height of each pyramid is [tex]\frac{1}{3} h[/tex] units.
C. The height of each pyramid is [tex]\frac{1}{6} h[/tex] units.
D. The height of each pyramid is [tex]$h$[/tex] units.



Answer :

To solve the problem, we need to compare the volumes of the cube and the pyramids with a common base. Let's begin by identifying the essential properties and calculating the volumes step-by-step.

1. Volume of the Cube:
- The cube has a height [tex]\( h \)[/tex], and since it is a cube, all sides are equal to [tex]\( h \)[/tex].
- The volume [tex]\( V_{cube} \)[/tex] of the cube is given by:
[tex]\[ V_{cube} = h^3 \][/tex]

2. Volume of a Square Pyramid:
- The volume [tex]\( V_{pyramid} \)[/tex] of a square pyramid with a base area [tex]\( A \)[/tex] and height [tex]\( H \)[/tex] is given by:
[tex]\[ V_{pyramid} = \frac{1}{3} \times \text{Base Area} \times \text{Height} \][/tex]
- Since the base of each pyramid is the same as the base of the cube and assuming the base area (A) is [tex]\( h^2 \)[/tex], we have:
[tex]\[ V_{pyramid} = \frac{1}{3} \times h^2 \times H_{pyramid} \][/tex]

3. Equating Volumes:
- We are given that six identical pyramids fill the same volume as the cube. Thus:
[tex]\[ 6 \times V_{pyramid} = V_{cube} \][/tex]
- Substituting the volumes, we get:
[tex]\[ 6 \times \left(\frac{1}{3} \times h^2 \times H_{pyramid}\right) = h^3 \][/tex]
- Simplifying:
[tex]\[ 2 \times h^2 \times H_{pyramid} = h^3 \][/tex]
- Solving for [tex]\( H_{pyramid} \)[/tex]:
[tex]\[ 2 \times h^2 \times H_{pyramid} = h^3 \][/tex]
[tex]\[ H_{pyramid} = \frac{h^3}{2 \times h^2} \][/tex]
[tex]\[ H_{pyramid} = \frac{h}{2} \][/tex]

4. Choosing Correct Options:
- The given options are:
[tex]\[ \text{The height of each pyramid is } \frac{1}{2} h \text{ units.} \][/tex]
[tex]\[ The height of each pyramid is \frac{1}{3} h \text{ units.} \][/tex]
[tex]\[ The height of each pyramid is \frac{1}{6} h \text{ units.} \][/tex]
[tex]\[ The height of each pyramid is h \text{ units.} \][/tex]

5. Conclusion:
- From the calculations, the height of each pyramid is found to be [tex]\( \frac{1}{3} h \)[/tex] units.
- Therefore, the correct answer is:
[tex]\[ The height of each pyramid is \frac{1}{3} h \text{ units.} \][/tex]