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A person standing on the bank of a river...

A person standing on the bank of a river observes that the angle subtended by a tree on the opposite bank is `60^(@)`. When he retires 40m from the bank, he finds the angle to be `30^(@)`. The breadth of the river is

A

` 20 sqrt3 mt`

B

` 25 mt`

C

` 20 mt`

D

` 30 mt`

Text Solution

Verified by Experts

The correct Answer is:
C
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AAKASH SERIES-PROPERTIES OF TRIANGLES-EXERCISE - 1
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  2. The angle of elevation of an object from a point P on the level ground...

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  3. The shadow of the tower standing on a level ground is found to be 60 m...

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  4. A person standing on the bank of a river observes that the angle subte...

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  5. The angle of elevation of the top of an unfinished tower from a point ...

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  6. If a flag staff of 6 mt high placed on the top of a tower throws a sha...

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  7. A sphere of radius 'a' subtends an angle 60^(@) at a point P. Then the...

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  8. Two tress A and B are on the same side of a river . From a point C in ...

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  9. Two ships leave a port at the same time . One goes 24km per hour in th...

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  10. If tan "" (A ) /(2) = (5)/(6) , tan "" ( B)/(2) = ( 20 )/( 37) " t...

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  11. In a triangle ABC if (cos A)/a=(cos B)/b= (cos C)/c, then Delta ABC is

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  12. In Delta ABC, if sin C=(sin A)/(2 cos B) then the triangle is

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  13. The angle of elevation of the sun when length of the shadow of a pole ...

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  14. The elevation of an object on a hill is observed from a certain point...

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  15. A flag staff of length 10 mt stands on a tower if from a point on the ...

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  16. The shadow of a tower standing on a level plane is found to be 50 mt l...

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  17. A tree stands vertically on the slant of the hills From a point A on t...

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  18. If Delta ABC is such that angle A = 90 ^(@) , angle B ne angle C " ...

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  19. In Delta ABC, if 8R^(2) = a^(2) + b^(2) + c^(2), then the triangle is ...

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  20. In Delta ABC, if 2R + r = r(2) then angleB =

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