Answer:
its 31.5
Step-by-step explanation:
first use the law of cosines to find the largest angle
since 13 is the longest side then angle C is the largest angle
so
[tex] {c}^{2} = {a}^{2} + {b}^{2} - 2ab \cos(c) [/tex]
so its
[tex]169 = 137.36 - 131.6 \cos(c) \\ 31.64 = - 131.6 \cos(c)[/tex]
then ÷ the equation by -131.6 and find the cos inverse of the angle to get C=76
after that use the law of sines
[tex] \frac{a}{ \sin(a) } = \frac{c}{ \sin(c) } [/tex]
then u get sinA =0.52
and again use sin inverse
so A= 31.5
