ZABC is a quadrilateral and OZCB is a trapezium in which OZ // CB and ∠AZC = 113°, ∠ZCB = 128°, ∠ABC = 62° and CB = CZ. Find
- ∠ZAO
- ∠CZO
- ∠ZBC.
(a)
∠ZAO
= 360° - 128° -113° - 62°
= 57° (Sum of angles in a quadrilateral)
(b)
∠CZO
= 180° - 128°
= 52° (Interior angles, ZO//CC)
(c)
∠ZBC
= (180° - 128°) ÷ 2
= 52 ÷ 2
= 26° (Isosceles triangle)
Answer(s): (a) 57°; (b) 52°; (c) 26°