PSLE QRST and RTUV are rhombuses. SWT is a straight line.
- Find ∠TRW.
- Find ∠STU.
(a)
∠RTS
= (180° - 106°) ÷2
= 74° ÷ 2
= 37° (Isosceles triangle)
∠TRW
= 180° - 128° - 37°
= 15° (Angles sum of triangle)
(b)
∠RVU
= 360° - 303°
= 57° (Angles at a point)
∠RTU = ∠RVU = 57° (Rhombus)
∠STU
= 57° - 37°
= 20°
Answer(s): (a) 15°; (b) 20°