What is an angle?

The video tutorial introduces the concept of angles in precalculus, defining an angle as the distance between two rays rotated about a vertex. It explains how angles are often denoted using Greek letters like Theta, beta, and alpha, instead of algebraic variables. The tutorial also covers the components of an angle, including the initial and terminal sides, and emphasizes the use of Greek symbols when the angle measure is unknown.

Explain the concept of initial and terminal sides of an angle.

How is the measurement of an angle determined according to the text?