PSLESTUV is a parallelogram, SUW is an equilateral triangle and UV = VW.
- Find ∠SUV.
- Find ∠UVS.
- Find ∠WST.
(a)
UV = VW
Triangle UVW is an isosceles triangle.
∠VUW
= (180° - 138°) ÷ 2
= 42° ÷ 2
= 21° (Isosceles triangle)
∠SUV
= 60° - 21°
= 39° (Equilateral triangle)
(b)
∠SWV
= 60° - 21°
= 39° (Equilateral triangle)
∠SVW
= 180° - 39° - 21°
= 120° (Angles sum of triangle)
∠SVU
= 360° - 138° - 120°
= 102° (Angles at a point)
∠TSU
= ∠SUV
= 39° (Alternate angles)
∠TSW
= 60° + 39°
= 99°
Answer(s): (a) 39°; (b) 102°; (c) 99°