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A ladder 15 m long makes an angle of 60 degrees with the wall. The height of the wall reached by the ladder is
A15 (square root of 3)/2 m
B7.5 m
C15/2 m
D15 m
Answer & Solution
Correct answer: B. 7.5 m
1. Angle with the wall = 60 degrees means angle with floor = 30 degrees.
2. Wall height = ladder × cos(60 degrees) = 15 × 1/2.
3. Hence 7.5 m.
_Source: NCERT Class 10 Mathematics, Ch 9 "Some Applications of Trigonometry", §9.2_
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