Examine the diagram of the triangle at right.

1. Write an equation representing the relationship of the side lengths using only $x, y,$ and $r$.

   Hint (a):

   Use the pythagorean theorem.

2. Write an expression for $\sin(θ)$. What is $\sin(θ)$ if $r = 1$?

   Answer (b):

   If $r = 1$, then  $\sin(θ) = y$.

3. Write an expression for $\cos(θ)$. What is $\cos(θ)$ if $r = 1$?

   Answer (c):

   If $r = 1$, then $\cos(θ) = x$.