Answer:
Final answer is C. 28°.
Step-by-step explanation:
Given equation is [tex]15^2+17^2-2\left(15\right)\left(17\right)\cos\left(\theta \right)=8^2[/tex].
Now we need to find the missing value of [tex]\theta[/tex] using cosine formula. So let's compare the given equation [tex]15^2+17^2-2\left(15\right)\left(17\right)\cos\left(\theta \right)=8^2[/tex] with cosine formula [tex]b^2+c^2-2\left(b\right)\left(c\right)\cos\left(A\right)=a^2[/tex].
we get [tex]\theta =A[/tex]
which is basically the angle between given sides 15 and 17
Hence A=28°.
So the final answer is 28°.
