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Aptitude - Height and Distance - Discussion

Discussion Forum : Height and Distance - General Questions (Q.No. 4)
Height and Distance
4.
An observer 1.6 m tall is 203 away from a tower. The angle of elevation from his eye to the top of the tower is 30°. The height of the tower is:
21.6 m
23.2 m
24.72 m
None of these
Answer: Option
Explanation:

Let AB be the observer and CD be the tower.

Draw BE CD.

Then, CE = AB = 1.6 m,

      BE = AC = 203 m.

DE = tan 30° = 1
BE 3

DE = 203 m = 20 m.
3

CD = CE + DE = (1.6 + 20) m = 21.6 m.

Discussion:
19 comments Page 1 of 2.
Abirami said:   5 years ago
Opp/adj is cos not tan.

So, the answer is 31.6.

Thus none of these is the answer.
(3)
Pooja Kale said:   6 years ago
Remember basic rule,

If Finding :
Perpendicular : Sin
Hypotenuse : cos
Base : tan
(3)
Vivek Sunny said:   4 years ago
No @Abirami..

cos = adjacent/hypotenuse

tan= opposite/adjacent

For simply, remember...

SOHCAHTOA

where,
s- Sin.
o- Opposite.
h- Hypotenuse.
c- Cos.
t- Tan.
(2)
Jatin007 said:   9 years ago
Applying tan because of we need to find DE.
So tan 30= DE/BE.
tan 30=DE/20√3,
DE=20√3*tan30( value of tan 30=1/√3),
So DE= 20.

So CD= EC+ED=1.6+20=21.6(answer).
(2)
Monu_yadav said:   9 years ago
But the unit of 20√3 is not given in a problem. So,answer is None of these.
(2)
Kesavan said:   7 years ago
I'm not getting whether to use tan or cos. Please, anyone, clarify it in detail.
(1)
Rocky said:   8 years ago
The correct answer is 61.6 so none of these is the correct option.
(1)
Seeli said:   8 years ago
Why they not use cos 30?
Vishakha said:   5 days ago
I agree with you @Abirami.

Thanks for explaining the answer.
Dipakk said:   7 years ago
@Jatin.

Why EC & ED added?
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