South Africa is 31% larger than Nigeria.
Area: 923,768 km2 World Factbook
Population: 177,155,754 (July 2014) World Factbook
Nigeria, officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. Wikipedia
Area: 1,214,470 km2 World Factbook
Population: 48,375,645 (July 2014) World Factbook
South Africa, officially the Republic of South Africa, is a country located at the southern tip of Africa. It has 2,798 kilometres of coastline that stretches along the South Atlantic and Indian oceans. Wikipedia