About what percent of Africa is desert? savanna?

25 percent

Explanation:

More than 25 percent of Africa is desert. The three deserts found in African continent are Sahara desert, Kalahari desert and Namib desert. The Sahara is the largest desert in the world and its spread over an area of 3.3 sq. miles. It is located in the northern part of Africa, while 65 percent of Africa is covered by Savanna.