PSLE Joelle has a triangular piece of paper BCD with CB = CD, ∠BCD = 82° and ∠DEE = 75°. BED and CED are straight lines. She folded it along the line EF as shown.
- Find ∠g.
- Find ∠h.
(a)
Length of BC = Length of CD
Triangle BCD is an isosceles triangle.
∠CDB
= (180° - 82°) ÷ 2
= 98° ÷ 2
= 49° (Isosceles triangle)
∠g
= 180° - 75° - 49°
= 56° (Angles sum of triangle)
(b)
∠CBD = ∠CDB = 49°
∠j
= 180° - 75° - 75°
= 30° (Angles on a straight line)
∠h
= 180° - 49° - 30°
= 101° (Angles sum of triangle)
Answer(s): (a) 56°; (b) 101°