STUV is a quadrilateral and OSVU is a trapezium in which OS // VU and ∠TSV = 111°, ∠SVU = 128°, ∠TUV = 63° and VU = VS. Find
- ∠STO
- ∠VSO
- ∠SUV.
(a)
∠STO
= 360° - 128° -111° - 63°
= 58° (Sum of angles in a quadrilateral)
(b)
∠VSO
= 180° - 128°
= 52° (Interior angles, SO//VC)
(c)
∠SUV
= (180° - 128°) ÷ 2
= 52 ÷ 2
= 26° (Isosceles triangle)
Answer(s): (a) 58°; (b) 52°; (c) 26°