From the question, we can see that:
AB = 5
BC = 5
Therefore, we have that:
AC = AB + BC ---> AC = 5 + 5 ---> AC = 10, as we can see in the example.
What we can see from the tool is that you can move the point B to the left or to the right so you can understand the segment addition postulate.
For example, you can move point B so that AB now be equal to 4. Then, the value for the segment BC is now 6. Then, AB = 4 and BC = 6, and AB + BC = AC ---> 4 + 6 = 10.
In summary, we can move the point B as we want to the right or to the left of the segment of the line AC, we always will have that:
AB + BC = AC.
