In the figure, DE is a straight line. ∠CFD = 90°, ∠GFH is equal to ∠HFE but 21° more than ∠CFG.
- What line is perpendicular to DE?
- Find ∠GFH.
(a)
Line CF or FC is perpendicular to DE
(b)
∠GFH = ∠HFE = 1 u
∠CFG = 1 u - 21°
1 u + 1 u + 1 u - 21° = 90° (Right angle)
3 u = 90° + 21° = 111°
1 u = 111° ÷ 3 = 37°
Answer(s): (a) CF or FC; (b) 37°