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:
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).
Subtract 80 on both sides:
Divide both sides by -64:
Now do the inverse of cosine of both sides or just arccos( )
[these are same thing]
Time for the calculator:
X=129.8 approximately
