Nigeria's physical frame: 923,768 sq km, the Niger and the Benue, and Chappal Waddi at 2,419 m
Background
Nigeria has a land area of 923,768 square kilometres. The country's official portal records that on the west and north it is bordered by the Republics of Benin and Niger respectively, that on the east it adjoins the Cameroon Republic, and that the Gulf of Guinea lies to the south. The Niger and the Benue are its principal rivers, the Benue being the Niger's largest tributary. In the east the Cameroon Highlands rise to the highest point in the country, Chappal Waddi, at 2,419 metres. Nigeria has a tropical climate with variable rainy and dry seasons depending on location. The portal groups the country's states in six regions: North Central, North East, North West, South West, South East and South South.
In plain words
Chappal Waddi Chappal Waddi — The highest point in Nigeria, at 2,419 metres in the Cameroon Highlands in the east of the country.
Tributary Tributary — A river that flows into a larger river; the Benue is the Niger's largest tributary.