Judging from both the chart and the photo, how can you use this document to argue that building the Great Wall was not worth the cost?

Yes, the construction of the great wall of China was worth the cost because it was built for the protection of the people from invasion at that time and the goal was achieved.

Explanation:

This great wall of China is built in order to secure the area from the outside attacks and stop the enemies from entering the state. This wall act as a barrier that protects the Chinese people in many invasion and the enemies are unable to enter the state. So we can say that the building of the great wall of China is worth it.

i'm free to do it

explanation:

the roman empire began to fall