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A TV tower stands vertically on a bank of a canal. From a point on the otherbank directly opposite the tower, theangle of elevation of the top of thetower is 60°. From another point 20 maway from this point on the line joingthis point to the foot of the tower, theangle of elevation of the top of thetower is 30° (see Fig. 12.12). Find theheight of the tower and the width ofthe canal. |
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Answer» -STEP EXPLANATION:ANSWERIN the figure, let AB be the TOWER and AC be the canal. C is the point on the other SIDE of the canal directly opposite the tower.Let AB=h,CA=x and CD=20From right △BAC.cot60o=x/h1/3=x/hx=h/3....(1)From right △BAD:cot30o=AD/AB3=(x+20)/hx=h3−20....(2)h=103From (1): x=(103)/3=10Therefore, the width of the canal is 10 m and height of the canal is 103 m.hope it helps |
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