I have a question regarding polygon data. I implemented "Calculate geometry" and the new column includes the area of interest to ha. The problem is with the accuracy of the data. The site area which is presented in the following image has different values from the derived area from ArcMap 10.5. In detail, the site area has a sum of 503645.235092 ha, and the area from "Calculate geometry" 528045.547832 ha. I used as a projected coordinate system the "ETRS89 / Albania TM 2010".
Why did this happen and is there another way to calculate the area?
Ideally, I would like those results to be the same.