A rectangular pyramid has a length of 7 cm and a width of 9 cm. Its volume is 231 cubic centimeters.

Use the formula for the volume of a pyramid to calculate the height of this pyramid. Show all your
work

1 answer

To calculate the height of the rectangular pyramid, we can use the formula for the volume of a pyramid:

\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]

In this case, the base area of the rectangular pyramid can be calculated by multiplying the length and the width of the base:

\[ \text{Base Area} = \text{Length} \times \text{Width} = 7 , \text{cm} \times 9 , \text{cm} = 63 , \text{cm}^2 \]

Now we can substitute the known values into the volume formula. We know that the volume \( V \) is 231 cubic centimeters:

\[ 231 = \frac{1}{3} \times 63 \times \text{Height} \]

To isolate the height, we can first multiply both sides by 3:

\[ 3 \times 231 = 63 \times \text{Height} \]

Calculating \( 3 \times 231 \):

\[ 693 = 63 \times \text{Height} \]

Next, we divide both sides by 63 to solve for the height:

\[ \text{Height} = \frac{693}{63} \]

Carrying out the division:

\[ \text{Height} = 11 , \text{cm} \]

Therefore, the height of the pyramid is

\[ \boxed{11 , \text{cm}} \]