A right square pyramid with base edges of length 8sqrt2 units each and slant edges of length 10 units each is cut by a plane that is parallel to its base and 4 units above its base. What is the volume, in cubic units, of the new pyramid that is cut off by this plane?
The length of the diagonal on the base of the pyramid = 8sqrt (2) * sqrt (2) =16
Hafl of this length = 8
Height of the pyramild = sqrt (10^2 - 8^2 ) = sqrt 36 = 6
Then the height of the smaller pyramid = 6 - 4 = 2
These pyramids are similar so the scale factor is 2/6 = 1/3
Volume of the larger pyramid = (1/3) side^2 * height = (1/3) (8sqrt (2) )^2 * 6 = 2 * 128= 256 units^3
Volume of smaller pyramid = volume of large pyramid * scale factor ^3 = 256 (1/3)^3 = 256/8 = 32 units^3