Everybody's hall is different so you have to measure your hall
* * * * *
The question is about one "half", not one "hall".
Unfortunately, the questioner does not say one and one half what (inch, foot, mile, micron, nanometre, etc) so it is impossible to give a sensible answer.
There are exactly 1.5 inches in one and one half inches.
100000 inches . * * * * * What? The answer depends on "one and one half" of what. But whatever that is, the answer is not likely to be 100000 inches!
1.5 inches.
6 inches in one half foot.
0.5 inches.
1.5 inches
six and one half
Eighteen inches.
42 inches
One yard and a half = 1.5 x 36 inches = 54 inches.
It is 54 inches.
There are two half-inches in one inch.