1. ## Cosine/Sine Law?

1.) A forty feet pole is braced by a wire from the top to a point 60 feet from its base up an 18° slope. How long is the wire? What angle does the wire makes with the ground?

I'm confused about the question. I have no idea exactly how the diagram looks like so I cant figure out which of the sine/cosine law must be used. Please help, and if possible please show me how the diagram looks like. Thanks!

2. I have drawn a figure

3. Originally Posted by malaygoel
I have drawn a figure

Could you please show the solution? I want to learn how to do it step by step. Thanks

4. Consider triangle CDE
........given CD,DE and angle CDE

cosine law:
$\displaystyle CE^2=CD^2+DE^2-2.CD.DE.cosCDE$

after CE is known,
sine law:
$\displaystyle \frac{CE}{sinCDE}=\frac{CD}{sinCED}$
...........hence angle CED can be determined.

5. ## thank you

thank you very much.

6. You would learn better by trying first! Look at the triangle CDE. You know that side DE has length 60 feet, CD has length 40 feet, and you should be able to determine angle CDE (hint: CD is perpendicular to AF). Knowing those three parts if the triangle, use sine and cosine laws you refer to in your title to find the other parts.