In \(\triangle PQR\), \(\angle P = 70°\) and \(\angle R = 30°\). Which side of this triangle is the longest?
Answer: C
First, find the third angle, \(\angle Q\).
\(\angle Q = 180° - (70° + 30°) = 180° - 100° = 80°\).
In any triangle, the side opposite the largest angle is the longest side.
The angles are P=70°, Q=80°, R=30°. The largest angle is \(\angle Q = 80°\).
The side opposite to \(\angle Q\) is PR. Therefore, PR is the longest side.