Answer:
Step-by-step explanation:
<u>Similar Triangles</u>
Lines ST and QR are parallel. Thus, angles S and Q are congruent, and angles T and R are congruent.
Considering the triangle PQR, the sum of its internal angles must be 180°:
Substituting the known values:
Solving for R:
Angles S and Q are congruent, thus
Angles T and R are congruent, thus
Summarizing: