Question

solve for angle c.
first, complete the equation.
$c^{2}=a^{2}+b^{2}-2ab\cos c$
$?^{2}=4^{2}+^{2}-2(4)()\cos c$
enter the side length that belongs in the green box.

Explanation:

Step1: Identify sides in cosine - law formula

In the cosine - law formula $c^{2}=a^{2}+b^{2}-2ab\cos C$, the side opposite the angle $C$ is $c$, and the other two sides are $a$ and $b$. Here, the side opposite angle $C$ has length $9$, and the other two sides have lengths $4$ and $7$.

Step2: Substitute values into the formula

We substitute $a = 4$, $b = 7$, and $c = 9$ into the formula. So, $[9]^{2}=4^{2}+[7]^{2}-2(4)([7])\cos C$.

Answer:

9