+128475 Last one before I head off to bed.....
(a) They are similar because the corresponding sides are in the same ratio
36/30 = 48/40
6/5 = 6/5
This is also the scale factor of the larger prism base to the smaller prism base
(b) If the prisms are the same height......the prism with base DEF will have a greater volume
It will be (Scale Factor)^2 greater than the smaller prism = (6/5)^2 = 36/25 times as great
