The sum of exterior angles = 360°
\(60° + 2(90 - m)° + 2(30 + 2m)° = 360°\)
\(60° + 180° - 2m° + 60° + 4m° = 360°\)
\(300° + 2m = 360°\)
\(\implies 2m = 360° - 300° = 60°\)
\(m = 30°\)
(b)



In \(\Delta QRS, \cos Q = \frac{\sqrt{3}}{2}\)
\(\cos Q = 0.8660 \implies Q = 30°\)
\(\therefore < SQR = 30°^\)
\(< PQS = 180° - 30° \) (angles on a straight line = 180°)
\(< PQS = 150°\)