# Adjacent Angles

**Adjacent angles** are two angles that share a common vertex and a side, with their other sides lying on the same straight line.

In simpler terms, two angles are adjacent if they are consecutive and their non-shared sides form a straight line.

The sum of two adjacent angles is always equal to a straight angle (180° or π radians).

Thus, adjacent angles are also **supplementary angles**, and vice versa.

**The difference between adjacent and consecutive angles**. It's important to note that two adjacent angles are always consecutive. However, the reverse isn't always true: two consecutive angles aren't necessarily adjacent. This is because __the sum of two adjacent angles is always 180°, while the sum of two consecutive angles can vary__. Both adjacent and consecutive angles share a vertex and a side. The key feature of adjacent angles is that their non-shared sides are aligned. In contrast, for consecutive angles, the non-shared sides might not be aligned.

## A Practical Example

Consider two angles:

$$ \alpha = 60° $$

$$ \beta = 120° $$

These two angles share a common vertex and a side, with their other sides aligned on the same straight line.

Therefore, these two angles are **adjacent angles**.

The sum of the two angles is 180°

$$ \alpha + \beta = 180° $$

And so on.