The formula to find the volume of a pyramid is length times width times height then divide all by 3. l x w x h / 3
A is 400cm because 10 x 10 x 12 equals 1200. 1200 / 3 is 400.
The formula for a triangular pyramid is apothem length times side length times height. Then divide all by 6. a x b x h / 6
B is 28cm because 4 x 6 x 7 equals 168. 168 / 6 is 28.