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A guy wire makes a 67° angle with the ground. Walking out 32 feet further from the tower, the angle of elevation to the top of the tower is 39°. Find the height of the tower.A. 40 ftB. 86 ftC. 48 ftD. 58 ft

A guy wire makes a 67° angle with the ground. Walking out 32 feet further from the-example-1
User Nicolas Dorier
by
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1 Answer

22 votes
22 votes

The height of the tower will be given by:


\tan\theta=(opposite)/(adjacent)

Where:

opposite = h

adjacent = x

tetha = 67°

Therefore:


\tan67=(h)/(x)

Solve for h:


\begin{gathered} x\cdot\tan67=x\cdot(h)/(x) \\ h=x\cdot\tan67 \end{gathered}

And for the other angle:


\tan39=(h)/(x+32)

Solve for h:


h=(x+32)\cdot\tan39

Equating the two equations for h, we have:


x\tan67=(x+32)\tan39

Now, solve for x:


\begin{gathered} x(2.36)=(x+32)(0.81) \\ 2.36x=0.810x+25.92 \\ 2.36x-0.81x=0.81x+25.92-0.81x \\ 1.55x=25.92 \\ (1.55x)/(1.55)=(25.92)/(1.55) \\ x=16.72\approx17 \end{gathered}

Now, we find h:


h=17\cdot\tan67=40.05\approx40

Answer: A 40 ft

User Wolfc
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2.8k points