PSLE Joelle has a triangular piece of paper MNP with NM = NP, ∠MNP = 84° and ∠PQQ = 66°. MQP and NQP are straight lines. She folded it along the line QR as shown.
- Find ∠s.
- Find ∠t.
(a)
Length of MN = Length of NP
Triangle MNP is an isosceles triangle.
∠NPM
= (180° - 84°) ÷ 2
= 96° ÷ 2
= 48° (Isosceles triangle)
∠s
= 180° - 66° - 48°
= 66° (Angles sum of triangle)
(b)
∠NMP = ∠NPM = 48°
∠u
= 180° - 66° - 66°
= 48° (Angles on a straight line)
∠t
= 180° - 48° - 48°
= 84° (Angles sum of triangle)
Answer(s): (a) 66°; (b) 84°