These are landmasses of 3 states 1 is Ogun state from the Southwest &amp; the rest are 2 states which are both Enugu &amp; imo states from southeast region. 
Here are maths
Enugu-7161kms+Imo-5530=12,691
Ogun state is 16,850
Total landmass of Enugu &amp; Imo= 12,691- Ogun=16850=4,159