2017 · Q80
ABCDEF is a regular polygon. Two poles at C and D are standing vertically and subtend angles of elevation 30° and 60° at A respectively. What is the ratio of the height of the pole at C to that of the pole at D ?
Elementary MathematicsTrigonometry
- A1:1
- B1 : 2√(3)
- C2√(3) : 1
- D2 : √(3)
Explanation
In regular hexagon ABCDEF with side s: AC = s√3 and AD = 2s. Pole at C: h_C = AC·tan30° = s; pole at D: h_D = AD·tan60° = 2s√3. Ratio h_C:h_D = 1:2√3: option B.