Answer:
Step-by-step explanation:
Let's draw the given information first for better understanding . Check the image attached.
We can use cosine rule to find the angles .
for angle A ,
[tex]Cos A =\frac{b^2+c^2-a^2}{2bc}[/tex]
[tex]Cos A =\frac{20^2+12^2-15^2}{2*20*12}[/tex]
[tex]Cos A =\frac{319}{480}[/tex]
m∠A = 48.35 degrees
Similarly for angle B
[tex]Cos B =\frac{a^2+c^2-b^2}{2bc}[/tex]
[tex]Cos B =\frac{15^2+12^2-20^2}{2*15*12}[/tex]
[tex]Cos B =\frac{-31}{360}[/tex]
m∠B = 94.94 degrees
Now use A+B+C=180 degrees
48.35+94.94+C=180
C=180-48.35-94.94
m∠C = 36.71 degrees
