All Circles Are Similar Practice Test

A surveyor measures triangle sides $a = 80\text{ m}$, $b = 65\text{ m}$, and $c = 50\text{ m}$ (opposite angles $A$, $B$, and $C$ respectively). Using the measurements, which law should be applied first to find an angle of the triangle?

In triangle $\triangle ABC$ formed during a construction layout, the measured sides are $AB=90\text{ m}$, $AC=70\text{ m}$, and $BC=50\text{ m}$. Using the measurements, which law should be applied first to solve for an angle of the triangle (such as $\angle A$)?