Earlier quoted context omitted.
North America is ~9.5 million sq mi and Africa is ~11.7 million sq mi according to Wikipedia...
USA is 10,000 square KM and Africa is 30,000 sq KM http://kai.sub.blue/en/africa.html
A square that is 100km on both sides is 10,000 square km. I always imagined the US was larger than that.