remember
longest side must be less than the sum of the other 2 sides
or
if c is longest and other 2 sides are a and b
c<a+b
if we assume x is longest
x<8.5+8
x<16.5
that is the max
if we assume 8.5 is biggest
8.5<8+x
minus 8
0.5<x
xo
0.5<x<16.5 is answer