The formula to calculate the volume of a rectangular pyramid is given by:
Volume = (1/3) * base area * height
Given that the base of the rectangular pyramid is a rectangle with dimensions of 12cm and 4cm, the base area would be:
Base area = length * width
Base area = 12cm * 4cm
Base area = 48cm^2
Given that the height of the pyramid is 3cm, we can substitute these values into the formula:
Volume = (1/3) * 48cm^2 * 3cm
Volume = 16 * 48
Volume = 768 cm^3
Therefore, the volume of the rectangular pyramid is 768 cm^3.