**Problem : **
If an arc of the unit circle has length
, what is the measure of the central
angle that intercepts that arc?

**Problem : **
The coordinates of a point on the unit circle are
(0, sin(*s*)). What is the value of *s*?

**Problem : **
An angle in standard
position intercepts the unit circle at (*x*, *y*). The
arc between (1,0)
and (*x*, *y*) has length *s*. Solve for *x* and *y* in terms of *s*.

**Problem : **
The $x$-coordinate of a point on the unit circle is
. What are the
possible y-coordinates?

**Problem : **
Is the equation for the unit circle a function?

Take a Study Break!