PSLE Winnie has a triangular piece of paper BCD with CB = CD, ∠BCD = 76° and ∠DEE = 71°. 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° - 76°) ÷ 2
= 104° ÷ 2
= 52° (Isosceles triangle)
∠g
= 180° - 71° - 52°
= 57° (Angles sum of triangle)
(b)
∠CBD = ∠CDB = 52°
∠j
= 180° - 71° - 71°
= 38° (Angles on a straight line)
∠h
= 180° - 52° - 38°
= 90° (Angles sum of triangle)
Answer(s): (a) 57°; (b) 90°