To find the volume of a rectangular pyramid, you can use the formula:
\[ \text{Volume} = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]
First, we need to calculate the base area. For a rectangular pyramid, the base area is given by:
\[ \text{Base Area} = \text{length} \times \text{width} \]
Substituting the given dimensions:
\[ \text{Base Area} = 4 , \text{cm} \times 3 , \text{cm} = 12 , \text{cm}^2 \]
Next, we use the height of the pyramid, which is given as 12 cm. Now we can substitute the base area and height into the volume formula:
\[ \text{Volume} = \frac{1}{3} \times 12 , \text{cm}^2 \times 12 , \text{cm} \] \[ \text{Volume} = \frac{1}{3} \times 144 , \text{cm}^3 \] \[ \text{Volume} = 48 , \text{cm}^3 \]
Thus, the volume of the rectangular pyramid is:
\[ \boxed{48} , \text{cm}^3 \]