To find the height of the rectangular pyramid, we need to use the formula for the volume of a rectangular pyramid: (1/3) * base area * height. The base area can be calculated by multiplying the length and width (7 cm * 9 cm = 63 cm²). Let h be the height of the pyramid. According to the given information, the volume is 231 cm³. We can now set up the equation (1/3) * 63 cm² * h = 231 cm³. Solving this equation, we find that the height of the rectangular pyramid is 3.86 cm.
