3.2  Nature and structure of the Nigerian economy  Nigeria is the single largest geographical unit in West Africa. It occupies a land area of 923,768 square kilometers and lies entirely within the tropics with two main vegetation zones; the rain forest and Savannah zones, reflecting the amount of rainfall and its spatial distribution.
Structurally, the Nigerian economy can be classified into three major sectors namely primary/agriculture and natural resources; secondary – processing and manufacturing; and tertiary/services sectors. The economy is characterized by structural dualism.