To find the height of a rectangular pyramid, we can use the formula for the volume of a pyramid:
\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]
For a rectangular pyramid, the base area is length times width:
\[ \text{Base Area} = \text{Length} \times \text{Width} \]
Given:
- Length = 7 cm
- Width = 9 cm
- Volume (V) = 231 cm³
First, we find the base area:
\[ \text{Base Area} = 7 , \text{cm} \times 9 , \text{cm} = 63 , \text{cm}^2 \]
Now, we can plug the base area into the volume formula:
\[ 231 = \frac{1}{3} \times 63 \times \text{Height} \]
To isolate the height, we can first multiply both sides by 3:
\[ 3 \times 231 = 63 \times \text{Height} \]
Calculating the left side:
\[ 693 = 63 \times \text{Height} \]
Now, divide both sides by 63:
\[ \text{Height} = \frac{693}{63} \]
Calculating:
\[ \text{Height} = 11 , \text{cm} \]
So, the height of the pyramid is:
Height = 11 cm