Question

what is the length of $overline{lm}$?

Explanation:

Step1: Identify coordinates

The coordinate of point $L$ is 60 and of point $M$ is 80.

Step2: Calculate distance

The length of $\overline{LM}$ is found by subtracting the smaller - coordinate from the larger one. So, $LM=80 - 60$.

Answer:

20