I have started a new chapter and I am having problems solving #6. I'm not even sure what I should do to start. Any help would be greatly appreciated.
Start with number ione, and then work your way to the end.
Recall that $\displaystyle \sin\theta=\frac{opposite}{hypotenuse}$
Well, you have the opposite, but not the hypotenuse. To find the hypotenuse, use the pythagorean theorem.
After you have computed sin, cos, and tan... You can make use of double angle Identities to find the values of the others.
Check this out
Double-Angle and Half-Angle Formulas