NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Heights and Distances
NTA Abhyas 2020 · Mathematics · Heights and Distances
If the angles of elevation of the top of a tower from three...
If the angles of elevation of the top of a tower from three collinear points and on a line leading to the foot of the tower are and respectively, then the ratio , is
Options
- A2 : 3
- B
- C
- D
Correct answer
B.
Step-by-step solution
tan {30}^{o} = \dfrac{h}{x + y + z}, tan {45}^{0} = \dfrac{h}{y + z}, tan {60}^{0} = \dfrac{h}{z} ⇒ x + y + z = \sqrt{3}h ... (i) y + z = h ... (ii) z = \dfrac{h}{3}... (iii)from (ii) & (iii)y = h \left(1 - \dfrac{1}{\sqrt{3}}\right) ... (iv)from (i) & (ii) h