Question

A.15
B.12
C.10
D.7
E.4
F.2

Answer 1

The triangle inequality requires that the sum of the shorter sides, a, b of a triangle be greater than the third side c.

This means that

a+b > c

If the third side is the longest, then a=6, b=9, and c<15

That makes 15 an impossible side.

If the third side x is less than 9, then

6+x<9, that makes

x<9-6=3.

That makes 2 an impossible side.

So the possible sides are 4,7,10,12,