In the figure, QSU and RST are straight lines. SQ = SR and TS = TU. If ∠RQS = 60°, find
- ∠QST
- ∠STU
(a)
∠QST
= 60° + 60°
= 120° (Exterior angle of a triangle)
(b)
∠TSU
= 180° - 120°
= 60° (Angles on a straight line)
∠STU
= 180° - 60° - 60°
= 60° (Isosceles triangle)
Answer(s): (a) 120°; (b) 60°