A TV tower stands vertically on a bank of canal From a

A TV tower stands vertically on a bank of canal From a
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A TV tower stands vertically on a bank of canal. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is 60. From another point 20 m away from this point on the line joining this point to the foot of the tower, the angle of elevation of the top of the tower is 30. Find the height of the tower and the width of the canal.

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Right Answer is:

SOLUTION

In ABC          

ABBC=tan60

ABBC=3

BC=AB3 

 In ABD

 ABBD=tan30.  

ABBC+CD=13   

In  ΔABD,ABBD=tan30oABBC+CD=13ABAB3+20=13AB3AB+203=133AB=AB+2032AB=203AB=103 mBC=AB3=1033=10 m

Therefore, the height of the tower is​​​​​​​ 103 m and the width of the canal is 10 m