Answer :
according to the pythagorean theorem the square of the largest side must be equal to the addition of the other sides square
[tex]a^2+b^2=c^2[/tex]use the pythagorean theorem to prove
[tex]\begin{gathered} 10^2+5^2=15^2 \\ 100+25=225 \\ 125\ne225 \end{gathered}[/tex]the triangle is not a right triangle