Evaluate for the sine of an angle using the sum of two angles

The video tutorial explains how to split the angle 285 degrees into 225 and 60 degrees and apply the sine sum formula. It demonstrates the use of the unit circle to find coordinates for these angles and shows how to multiply and simplify these coordinates to solve trigonometric problems.

What is the significance of the unit circle in determining sine and cosine values?

Explain the process of multiplying the sine and cosine values as described in the text.