PSLE Sabrina has a triangular piece of paper EFG with FE = FG, ∠EFG = 82° and ∠GHH = 71°. EHG and FHG are straight lines. She folded it along the line HJ as shown.
- Find ∠k.
- Find ∠l.
(a)
Length of EF = Length of FG
Triangle EFG is an isosceles triangle.
∠FGE
= (180° - 82°) ÷ 2
= 98° ÷ 2
= 49° (Isosceles triangle)
∠k
= 180° - 71° - 49°
= 60° (Angles sum of triangle)
(b)
∠FEG = ∠FGE = 49°
∠m
= 180° - 71° - 71°
= 38° (Angles on a straight line)
∠l
= 180° - 49° - 38°
= 93° (Angles sum of triangle)
Answer(s): (a) 60°; (b) 93°