Given:
The triangle, LMN has side lengths of 18.5 inches, 10 inches, and 15.5 inches
Using the converse of the Pythagorean theorem
So,
[tex]\begin{gathered} 18.5^2=342.25 \\ 10^2=100 \\ 15.5^2=240.25 \\ 10^2+15.5^2=340.2\ne342.25 \end{gathered}[/tex]So, the triangle LMN is not a right-angle triangle
The order of proof is as follows:
[tex]\begin{gathered} 1)10^2+15.5^2=340.2 \\ 2)a^2+b^2=340.2 \\ 3)18.5^2=342.25 \\ 4)340.25\ne342.25 \\ 5)\text{LMN not right triangle} \end{gathered}[/tex]