Answer: 88meters
Explanation:
make a direct variation
so if a 2.8 meter building casts a 1.61 shadow then
2.8/1.61
and if a unknown building mark that as x gives a 50.75 shadow then
2.8/1.61=x/50.75
the you cross multiply that would give you 1.61x=142.1
then divide both sides by 1.61 you get x=88.2608696
But since it say round to the nearest meter you round to 88!