PSLE Hazel has a triangular piece of paper ABC with BA = BC, ∠ABC = 76° and ∠CDD = 66°. ADC and BDC are straight lines. She folded it along the line DE as shown.
- Find ∠f.
- Find ∠g.
(a)
Length of AB = Length of BC
Triangle ABC is an isosceles triangle.
∠BCA
= (180° - 76°) ÷ 2
= 104° ÷ 2
= 52° (Isosceles triangle)
∠f
= 180° - 66° - 52°
= 62° (Angles sum of triangle)
(b)
∠BAC = ∠BCA = 52°
∠h
= 180° - 66° - 66°
= 48° (Angles on a straight line)
∠g
= 180° - 52° - 48°
= 80° (Angles sum of triangle)
Answer(s): (a) 62°; (b) 80°