To determine the length of the base of the pyramid, we can use the formula for the volume of a pyramid:
\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]
The base area of the pyramid can be calculated as:
\[ \text{Base Area} = \text{Length} \times \text{Width} \]
In this case, let \( L \) be the length of the base and we know the width is \( 15 , \text{cm} \) and the height (altitude) is \( 9 , \text{cm} \). The volume \( V \) is given as \( 585 , \text{cm}^3 \).
Substituting into the volume formula:
\[ 585 = \frac{1}{3} \times (L \times 15) \times 9 \]
First, simplify the equation:
\[ 585 = \frac{1}{3} \times 15 \times 9 \times L \]
Calculating \( \frac{1}{3} \times 15 \times 9 \):
\[ \frac{1}{3} \times 15 = 5 \] \[ 5 \times 9 = 45 \]
So the equation now is:
\[ 585 = 45L \]
Next, solve for \( L \):
\[ L = \frac{585}{45} \]
Now, perform the division:
\[ L = 13 \]
Thus, the length of the base of the pyramid is \( 13 , \text{cm} \).
The correct response is:
13 cm.