If a scalene triangle has its measures 4 m, 11 m and 8 m, find the largest angle.A. 129.8B. 90.0C. 34.0D. 16.2​

Answer:129.8 approximately Step-by-step explanation:So this sounds like a problem for the Law of Cosines. The largest angle is always opposite the largest side in a triangle.So 11 is the largest side so the angle opposite to it is what we are trying to find. Let's call that angle, X.My math is case sensitive.X is the angle opposite to the side x.Law of cosines formula is:[tex]x^2=a^2+b^2-2ab \cos(X)[/tex]So we are looking for X.We know x=11, a=4, and b=8 (it didn't matter if you called b=4 and a=8).[tex]11^2=4^2+8^2-2(4)(8)\cos(X)[/tex][tex]121=16+64-64\cos(X)[/tex][tex]121=80-64\cos(X)[/tex]Subtract 80 on both sides:[tex]121-80=-64\cos(X)[/tex][tex]41=-64\cos(X)[/tex]Divide both sides by -64:[tex]\frac{41}{-64}=\cos(X)[/tex]Now do the inverse of cosine of both sides or just arccos( ) [these are same thing][tex]\arccos(\frac{-41}{64})=X[/tex]Time for the calculator:X=129.8 approximately