FGHJ is a square. HGH and GGJ are straight lines. GF = GH and ∠GGH = 15°. Find
- ∠GFH
- ∠JHH
.
(a)
∠FGJ = 45° (Right angle)
∠FGH
= ∠FGJ - ∠GGH
= 45° - 15°
= 30°
∠GFH
= (180° - ∠FGH) ÷ 2
= (180° - 30°) ÷ 2
= 150° ÷ 2
= 75° (Isosceles triangle)
(b)
GF = GH = GH
HGH is an isosceles triangle.
∠GHH = ∠GHH (Isosceles triangle)
∠GHH
= (180° - ∠JGH - ∠GGH) ÷ 2
= (180° - 45° -15°) ÷ 2
= 120° ÷ 2
= 60°
∠JHH
= ∠GHJ - ∠GHH
= 90° - 60°
= 30°
Answer(s): (a) 75°; (b) 30°
