Step-by-step explanation: You can use the pythagorean theorom to figure this one out. For all right traingles the sum of one of the smallest sides squared plus the sum of the other smallest side squared equal the biggest side squared or a^2+b^2=c^2. Which ever one of these doesnt fit the equation isnt a right traingle. 5^2+9^2=106, 11^2=121 106[tex]\neq[/tex]121.
