Hard question please help

Answer:
147.5kg
Step-by-step explanation:
l=12
h=5
diagonal=d
using Pythagorean theorum
d=sqrt of (12^2+5^2)
=13m
there are two diagonals
total meters (f)=26+2h+2l
f=25+10+24
=59m
if it is 2.5 kg pet metre
2.5×59=total weight
=147.5kg