What "structure" is being referred to in this sentence?

Question

I read this in my history book:

Generally (though not always), Al-Biruni adopted a distinctive structure in each chapter, beginning with a question, following this up with a description based on Sanskritik traditions, and concluding with a comparison with other cultures. Some present day scholars have argued that this almost geometric structure, remarkable for its precision and predictability, owed much to his mathematical orientation.

In the first sentence, it was said that the structure began with a question, followed up with a description..... with other cultures(suggesting that the "structure" was the way he wrote). But the latter sentence says that the structure was almost geometric which suggests figures and diagrams which contradicts the above one. I want to ask what does author really want to say about the "structure"?

Answer 1

We can use 'structure' in an abstract sense to talk about the way a piece of writing is composed ('constructed'). The author is saying that Al-Biruni planned each chapter in a precise and formal way, and compares this to the way proofs are written in geometry.