To solve the problem, we need to find the length of segment $RT$ using the given lengths of segments $RS$ and $ST$.

Given:

• $RS = 16$
• $ST = 9$

Since $R, S,$ and $T$ are points on a number line and are in a straight line, the length of $RT$ is the sum of the lengths of $RS$ and $ST$.

So, we can calculate $RT$ as follows:

$RT = RS + ST$

$RT = 16 + 9 = 25$

Thus, the length of $RT$ is 25.

Would you like more details or have any questions?

Here are 5 related questions you might find interesting:

1. How do we find the distance between two points on a number line?
2. What happens if the points are not in a straight line? How would you calculate the distance then?
3. Can you use this method for finding distances in a coordinate plane?
4. How would you handle a situation where one of the lengths is negative?
5. What is the difference between absolute and relative distances in math?

Tip: Always ensure that the points are in a straight line when using addition to find total lengths.