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An observer $1.5\mathrm{m}$ tall is $28.5\mathrm{m}$ away from a chimney. If the angle of elevation of the top of the chimney from her eyes is $45^{\circ}$, what is the height of the chimney? 
A$28.5\mathrm{m}$
B$29\mathrm{m}$
C$30\mathrm{m}$
D$30.5\mathrm{m}$
Answer & Solution
Correct answer: C. $30\mathrm{m}$
Let the height above the observer’s eye level be $h$. Since $\tan 45^{\circ}=1$, we get $h=28.5\mathrm{m}$. Adding the observer’s height, chimney height $=28.5+1.5=30\mathrm{m}$.
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