Question

In AABC, a = 13, b = 14, and c = 18. Find m/A.
B
A
39.5
с
b
a

Answer 1

Answer:

Step-by-step explanation:

Using the Law of Cosines,

$a^{2}=b^2 + c^2 - 2bc \cos A\\\\13^{2}=14^{2}+18^{2}-2(14)(18) \cos A\\\\-351=-504 \cos A\\\\\cos A=\frac{351}{504}\\\\A=\boxed{\cos^{-1} \left(\frac{351}{504} \right)}$