The length of the line segment is 3 units.
Let's determine the length of the line segment shown:

We can solve this problem by using the distance formula, which states that the distance between two points (x_1, y_1) and (x_2, y_2) is:

Plugging in the given points, we get:

Simplifying the expression, we get:

Evaluating the square root, we get:

Therefore, the length of the line segment is 3 units.