Because the curved Earth's surface is not isometric to a plane, preservation of shapes inevitably leads to a variable scale and, consequently, non-proportional presentation of areas.
Fal as arori n amdal ikrambay war eqqel a ogdahan id abyon , aɣalas n iššikilan itiwi s esăssar izlăyan d aɣălas war n ogdah i idăgan