The unit circle is an important tool for learning about angles that are bigger than 90 degrees in trigonometry.

1. What Are Angles?: Angles are measured by going counterclockwise from the positive x-axis. For example:

   • An angle of 120° is found in the second part of the chart (called the second quadrant).
   • An angle of 240° is in the third part (the third quadrant).

2. Finding Sine and Cosine: We can use the unit circle to find the sine and cosine for these angles:

   • For 120°, the coordinates are $\left(-\frac{1}{2}, \frac{\sqrt{3}}{2}\right)$. This means that $\sin(120°) = \frac{\sqrt{3}}{2}$ and $\cos(120°) = -\frac{1}{2}$.

3. Understanding the Values: This way of looking at the angles helps us see that sine and cosine can be positive or negative. However, they still have a steady relationship based on the circle's symmetry.