Question

solve for c.
first, complete the equation.
$c^{2}=a^{2}+b^{2}-2ab\cos c$
$c^{2}=3^{2}+?^{2}-2(3)()\cos$
enter the side length that belongs in the green box.

Explanation:

Step1: Identify side - lengths in the law of cosines

In the formula $c^{2}=a^{2}+b^{2}-2ab\cos C$, for the given triangle, if $a = 3$, the other non - unknown side length is $b=10$.

Step2: Complete the equation

The equation $c^{2}=3^{2}+[?]^{2}-2(3)(\text{?})\cos(\text{?})$ should be $c^{2}=3^{2}+10^{2}-2(3)(10)\cos34^{\circ}$. So the value in the green box is 10.

Answer:

10