Answer:
78.28023969=C
Step-by-step explanation:
The largest angle is opposite the largest side so C would be the largest angle.
We can find C using the law of cosines
c^2 = a^2 + b^2 -2ab cosC
13^2 = 12^2 +8^2 -2*12*8cosC
169 = 144 +64 - 192 cos C
Combine like terms
169 =208 - 192 os C
Subtract 208 from each side
-39 = -192 cos C
Divide by -192
-39/-192 = cos C
Take arccos of each side
acrcos (39/192) = arccos (cos C)
arccos (39/192) = C
78.28023969=C
