human
improve the text: It is useful to find another expression for $n^2/2$ so as to mathematically represent what the square grid in the plane with dimensions $n\times n$ constituted of unit area squares shows visually. 
gpt
--- Reasoning ---
1. Is the question multiple-choice question?
No
2. Is it implied multiple-choice question?
No
3. If two experts were independently asked the question, will the final answer be exactly the same?
No

--- Answer ---
open