A stone monument is the shape of a pyramid. The width of the base is 12 m and the length of the base is 9 m. The height of the monument is 15, and the stone weighs about 3000kg/m3. How many tonnes does the monument weigh? (2000 kg = 1 metric tonne)
V=(LxWxH)/3 so, V= (9x12x15)/3 = 1,620/3 = 540m^3. From here you multiply 540m^3 by 3,000kg/m^3 and get 1,620,000kg. Then you divide 1,620,000kg by 2,000kg/metric tonne and get 810 metric tonnes.