Answer:
0.5 < x < 15.5
Explanation:
Triangle Inequality Theorem
Let y and z be two of the side lengths of a triangle. The length of the third side x cannot be any number. It must satisfy all the following restrictions:
x + y > z
x + z > y
y + z > x
Combining the above inequalities, and provided y>z, the third size must satisfy:
y - z < x < y + z
The two side lengths given in the triangle of the figure are y=8.5, z=8.0, thus the possible values of x lie in the interval
8.5 - 8.0 < x < 8.5 + 8.0
0.5 < x < 15.5