WAEC - Mathematics (1999 - No. 12)

In the diagram, POR is a circle with center O. ∠QPR = 50°, ∠PQO = 30° and ∠ORP = m. Find m.

20^o

25^o

30^o

50^o

< QOR = 50° x 2 = 100°

Reflex < QOR = 360° - 100° = 260°

\(\therefore\) 30° + 50° + 260° + m = (4 - 2) x 180°

340° + m = 360°

m = 360° - 340° = 20°