Question

How did this structure combine both Greek and Roman architectural elements?

Answer 1

I believe they used the same materials and same patterns and designs. They combined their ways of building as well.

Answer 2

Greek and Roman architectures are two of the most influential architectures ever.

In the construction shown in the picture provided with the question, we can see that it combines both of them by using Corinthian Order, the pillars and the shapes of Roman Architecture. We can see a dome on top of the building which also relates to Roman Architecture.