The figure is not drawn to scale. ∠TSU = 41°, TS = TU and SX//TW. Given that ∠s is
13 of ∠q and ∠s is 4 times of ∠r, find
- ∠s
- ∠p
(a)
s : q = 1 : 3
q = 3 s
r : s = 1 : 4
q = 3 x 4= 12
q : r : s = 12 : 1 : 4
∠TUS = 41° (Isosceles triangle)
∠SUV
= 180° - 41°
= 139° (Angles on a straight line)
1 u + 4 u + 12 u + 139° = 360° (Sum of angles in a quadrilateral)
17 u = 360° - 139° = 221°
1 u = 221 ÷ 17 = 13°
∠s
= 4 x 1 u
= 4 x 13°
= 52°
(b)
∠TUS = ∠TSU = 41° (Isosceles triangle)
∠UYW = ∠USX = 52° (Corresponding angles, SX//TW)
∠p
= 52° - 41°
= 11° (Exterior angle of a triangle)
Answer(s): (a) 52°; (b) 11°
