The sum of the lengths of two sides of a triangle must always be less than or equal to the third side. So, if we let the third side be x, we have:
[tex]\begin{cases}6+x\geq9\\x+9\geq6\\6+9\geq x\end{cases} \iff \begin{cases}x\geq3\\x\geq -3\\x\leq 15\end{cases} \iff \begin{cases}x\geq3\\x\leq 15\end{cases}[/tex]
Answer:
anything between 3 and 15 BUT NOT 3 OR 15
they can be
4
5
6
7
8
9
10
11
12
13
14
