PSLE Emily has a triangular piece of paper QRS with RQ = RS, ∠QRS = 76° and ∠STT = 69°. QTS and RTS are straight lines. She folded it along the line TU as shown.
- Find ∠v.
- Find ∠w.
(a)
Length of QR = Length of RS
Triangle QRS is an isosceles triangle.
∠RSQ
= (180° - 76°) ÷ 2
= 104° ÷ 2
= 52° (Isosceles triangle)
∠v
= 180° - 69° - 52°
= 59° (Angles sum of triangle)
(b)
∠RQS = ∠RSQ = 52°
∠x
= 180° - 69° - 69°
= 42° (Angles on a straight line)
∠w
= 180° - 52° - 42°
= 86° (Angles sum of triangle)
Answer(s): (a) 59°; (b) 86°