Examining the markings on the angles, we can see that the triangles have two congruent angles, ∠ BAC and ∠ QSR as well as ∠ ABC and ∠ SQR. This means that they have the same measure. Let's add these pieces of information to the diagram.
According to the Third Angles Theorem, if two angles of one triangle are congruent to two angles of another triangle, then the third angles are also congruent. Therefore, the third angles will have equal measures. To find the measure of the remaining angle in △ ABC, we can use the Triangle Angle-Sum Theorem.
45^(∘)+80^(∘)+m∠ C = 180^(∘)
Let's solve this equation.
