Math, asked by batishjass001, 10 months ago

the angle of depression of the top and bottom of a 50 m high building from the top of a tower are 45 and 60 find the height of tower​

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Answered by dakshgovil
4

Answer:

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Step-by-step explanation:

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Answered by Anonymous
14

ANSWER:-

Given:

The angle of depression of the top & bottom of a 50m high building from the top of a tower are 45° & 60° respectively.

To find:

The height of the tower.

Solution:

Let AB be the tower of height h m & CD be the building of height 50m.

•Draw CL perpendicular to AB.

So,

⚫LB= CD= 50m

⚫AL= (h-50)m

⚫LC = BD

Let angle ACL= 45° &

angle ADB= 60°

In ∆ABD,

We know, [tan60° = √3]

 =  >  tan60 \degree =  \frac{AB}{BD}  \\  \\  =  >  \sqrt{3}  =  \frac{h}{BD}  \\  \\  =  >  \sqrt{3} BD = h \\  \\  =  > BD =  \frac{h}{ \sqrt{3} } ...................(1)

In ∆ALC,

We know [tan45°= 1]

  =  > tan45 \degree =  \frac{AL}{LC}  \\  \\  =  > 1 =  \frac{h - 50}{BD}  \\  \\  =  > BD = h - 50.................(2)

Comparing equation (1) & (2), we get;

 =  > h - 50 =  \frac{h}{ \sqrt{3} }  \\  \\  =  > h -  \frac{h}{ \sqrt{3} }  = 50 \\  \\  =  >  \sqrt{3} h - h = 50 \sqrt{3}  \\  \\  =  > h( \sqrt{3}  - 1) = 5 0\sqrt{3}  \\  \\  =  > h =  \frac{50 \sqrt{3} }{ \sqrt{3}  - 1} \\ [Rationalising] \\  \\  =  >  \frac{50 \sqrt{3}  \times  \sqrt{3} + 1 }{ \sqrt{3} - 1 \times  \sqrt{3} + 1  }  \\  \\   =  >  \frac{150 + 50 \sqrt{3} }{ { (\sqrt{3}) }^{2}  - ( {1)}^{2} }   \:  \:  \:  \:  \:  \: [{a}^{2}  -  {b}^{2}  = (a + b)(a - b)] \\  \\  =  >  \frac{150 + 50 \sqrt{3} }{3 - 1}  \\  \\  =  >  \frac{150 + 50 \sqrt{3} }{2}  \\  \\  =  > 75 + 25 \sqrt{3}  \\  \\  =  > 75 + 25\times 1.732 \\  \\  =  > (75 + 43.3)m \\  \\  =  >h =  118.3m

Thus,

The height of the tower is, h= 118.3m.

Hope it helps ☺️

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