The figure is not drawn to scale. ∠JHK = 41°, JH = JK and HN//JM. Given that ∠w is
12 of ∠t and ∠w is 4 times of ∠v, find
- ∠w
- ∠s
(a)
w : t = 1 : 2
t = 2 w
v : w = 1 : 4
t = 2 x 4= 8
t : v : w = 8 : 1 : 4
∠JKH = 41° (Isosceles triangle)
∠HKL
= 180° - 41°
= 139° (Angles on a straight line)
1 u + 4 u + 8 u + 139° = 360° (Sum of angles in a quadrilateral)
13 u = 360° - 139° = 221°
1 u = 221 ÷ 13 = 17°
∠w
= 4 x 1 u
= 4 x 17°
= 68°
(b)
∠JKH = ∠JHK = 41° (Isosceles triangle)
∠KPM = ∠KHN = 68° (Corresponding angles, HN//JM)
∠s
= 68° - 41°
= 27° (Exterior angle of a triangle)
Answer(s): (a) 68°; (b) 27°
