Use the diagram at right to calculate the exact values of the following trigonometric expressions.  

1. $\sin(α)$ 

   Hint (a):

   Use the values given in the diagram.

2. $\cos(α)$ 

   Hint (b):

   Calculate the length of the base of the triangle. What should the sign be?

3. $\tan(α)$ 

   Hint (c):

   Use the information in the triangle and your calculated base from part (b).