the longest side of a triangle must be less than the sum of the other 2 sides
2 senarios
the 3rd side is the longest
the 3rd side is not the longest
for the 3rd side is the longest
3rdside<28+42
3rdside<70
for 3rd side isn't the longest
42 is longest
42<28+3rdside
14<3rdside
so we've got
3rdside<70 and 14<3rdside
so
14<3rdside<70
the 3rd side can be any number from 14in to 70in except 14in and 70in
