PSLE Jaslyn has a triangular piece of paper STU with TS = TU, ∠STU = 82° and ∠UVV = 65°. SVU and TVU are straight lines. She folded it along the line VW as shown.
- Find ∠x.
- Find ∠y.
(a)
Length of ST = Length of TU
Triangle STU is an isosceles triangle.
∠TUS
= (180° - 82°) ÷ 2
= 98° ÷ 2
= 49° (Isosceles triangle)
∠x
= 180° - 65° - 49°
= 66° (Angles sum of triangle)
(b)
∠TSU = ∠TUS = 49°
∠z
= 180° - 65° - 65°
= 50° (Angles on a straight line)
∠y
= 180° - 49° - 50°
= 81° (Angles sum of triangle)
Answer(s): (a) 66°; (b) 81°