Conditions for side lenghts for triangle: a<b+c and b<c+a and c<a+b so we check all posibilities: A) 2+5=7 we can see that one condition is not fulfilled so they can't be side lenghts of triangle B) 9<14+17 14<9+17 17<14+19 All conditions are fulfilled so they can be side lenghts of triangle C)7<17+24 17<7+24 24<17+7 All conditions are fulfilled so they can be side lenghts of triangle D)5<12+13 12<5+13 13<5+12 All conditions are fulfilled so they can be side lenghts of triangle