Formation of an angle between lines

An angle formed between two lines which have common intersecting point is called an angle formed between the lines.

Example

An angle can be formed between two lines when they both have common intersecting point.

For example, $\overrightarrow{RS}$ and $\overrightarrow{RT}$ are two rays and they both are started from point $R$. Thus, an angle is formed between them.

The angle formed between them is represented by $\angle SRT$ or $\angle TRS$ mathematically.