Answer:
[tex]21^{\circ}[/tex]
Step-by-step explanation:
The Law of Sines is given by [tex]\frac{\sin A}{a}=\frac{\sin B}{b}=\frac{\sin C}{c}[/tex] and works for every triangle.
Substituting given values, we have the following equation:
[tex]\frac{\sin 68^{\circ}}{18}=\frac{\sin C}{7}, \\\\\sin C=\frac{7\sin 68^{\circ}}{18},\\\\C=\sin^{-1}(0.36057149899),\\\\C\approx \boxed{21^{\circ}}[/tex]
*Note that because [tex]\sin \theta=\sin(180-\theta)[/tex], when solving for an angle with the Law of Sines, there may be two answers. However, since the problem designates angle C as an acute angle, the other angle is negligible.
