48128m^3
Step-by-step explanation:
Given data
For the building
L=64m
W= 6m
H= 36m
The volume is
V= LWH/3
V=64*64*36/3
V=147456/3
V=49152m^3
For the off-Cut
L=16m
W= 16m
H= 12m
The volume is
V= LWH/3
V=16*16*12/3
V=3072/3
V=1024m^3
Hence the volume of the truncated part/Building
= Volume of building-volume of off-cut
=49152-1024
=48128m^3