Answer: a = 8
Step-by-step explanation:
Volume of a square based pyramid is given as
.
where a is the length of the side and h is the height.
Substituting into the formula , we have
V = 
128 =
/3
384=
X 6
Divide through by 6
384/6 = 
64 = 
Therefore :
a = 
a = 8
Its c first find area of the whole thing with piece cut out.(240) then of the cut out piece (12) 240-12=228 C
It would be obtuse.
Hope this helps :)