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CGP EDU Academic Team
Published on: August 14, 2026
A tower AB leans towards west making an angle a with the vertical. The angular elevation of B, the top most point of the tower, is 60° as observed from a point C due east of A at a distance of 10 ft from A. If the angular elevation of B from a point D due east of C at a distance of 20 ft from C is 45°, then the value of 2 tan a is equal to
A
B
C
D
Text Solution
Verified by ExpertsThe correct answer is:
C
By (m - n) theorem, we have
30 cot 60° = 10 cot 45° - 20cot 
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