Trigonometryhard · Past Paper
A vertical tower is surmounted by a flagstaff of height h. At a point on ground, elevations of bottom and top of flagstaff are α and β. Tower height is:
Ah tanα / (tanβ - tanα)
Bh tanβ / (tanβ - tanα)
Ch / (tanβ - tanα)
Dh tanα tanβ
✓ Correct Answer: A — h tanα / (tanβ - tanα)
H/d = tan α, (H+h)/d = tan β. H/tan α = (H+h)/tan β. H tan β = H tan α + h tan α. H = h tan α / (tan β - tan α).
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