In the figure, QSU and RST are straight lines. SQ = SR and TS = TU. If ∠RQS = 57°, find
- ∠QST
- ∠STU
(a)
∠QST
= 57° + 57°
= 114° (Exterior angle of a triangle)
(b)
∠TSU
= 180° - 114°
= 66° (Angles on a straight line)
∠STU
= 180° - 66° - 66°
= 48° (Isosceles triangle)
Answer(s): (a) 114°; (b) 48°