Answer:
The total area of the United States (including Alaska and Hawaii) is 9.6 million square kilometers (3.8 million square miles).
How big is the sub-Saharan Africa region?
9.4 million square miles
Landforms Ecologically separated from North Africa by the sweeping and sparsely populated Sahara Desert, the sub-Saharan mainland consists of four vast and distinct regions: Central Africa, East Africa, West Africa, and Southern Africa. Together, they constitute an area of 9.4 million square miles.