To find the length of a line segment, given the coordinates of its endpoints, we can use two methods.

**Example**

Find the **length **of the line segment **AC** whose endpoints are at**:**

**A(-5, -3)** and **C(3, -3)**.

**Method 1**

Plot the points and count the squares.

AC is 8** **units** **long. Just write **8**.

*This method is fine if you have paper and time, and the coordinates are small.*

**Method 2**

Subtract the relevant coordinates.

The x-coordinates of the endpoints of *vertical *lines will be the same.

The y-coordinates of the endpoints of *horizontal *lines will be the same.

**A is at (-5, -3)** and **C is at (3, -3)**.

The line AC is horizontal because the y-coordinates are both -3.

Subtract the x-coordinates: **-5** - **3** = -8 or **3** - **-5** = 8.

Ignore the sign: -8 or 8 means a length of 8** **units. Just write **8**.

*For vertical lines, we subtract the y-coordinates.*