Hello, jul07010!
I agree with u2_wa: we don't need the Law of Sines . . .
A point on the ground is 200 feet from a water tower.
The angle of elevation to the top of the tower is 18°.
The angle of elevation to the bottom of the tower is 15°.
How tall is the water tower?
(i think the water tower is on a hill?) yes! Code:
B *
| *
| *
h | *
| *
| *
C * *
| * *
| * *
y | 200 * 3° *
| * *
| 15° * *
D * - - - - - - - - - - - * A
x
The height of the tower is: 
Let 
is the ground: 
In right triangle ![CDA:\;\begin{array}{ccccccc}\sin15^o \:=\:\frac{y}{200} &\Rightarrow& y \:=\:200\sin15^o & {\color{blue}[1]}\\<br />
\cos15^o \:=\:\frac{x}{200} & \Rightarrow & x \:=\:200\cos15^o & {\color{blue}[2]} \end{array}](http://latex.codecogs.com/png.latex?CDA:\;\begin{array}{ccccccc}\sin15^o \:=\:\frac{y}{200} &\Rightarrow& y \:=\:200\sin15^o & {\color{blue}[1]}\\<br />
\cos15^o \:=\:\frac{x}{200} & \Rightarrow & x \:=\:200\cos15^o & {\color{blue}[2]} \end{array})
In right triangle 
.[3]
Substitute [1] and [2] into [3]: . \tan18^o - 200\sin15^o )
Therefore: . 
ft.
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Originally Posted by jul07010 
