At the height of the British Empire, the UK was the world's foremost manufacturing country and controlled around 25% of the world's land surface. Britain imported raw materials from its Empire (including many African countries) and exported manufactured goods to them in return.
yes, South Africa was formerly part of the British Empire
For gold
in 123bc
they got slave trade i think i dunno i'm not so good at these questions
Africa
By conquests from several European nations. The European nations had many firearms, and Africa and India did not have that many at all compared to the Europeans. This caused conquests and how India and Africa became part of the British Empire
The Suez Canal, which linked the Mediterranean Sea to the Red Sea, meaning that British ships did not have to sail around Africa to reach India, a hugely important route for British (and French trading).
cocoa, palm oil, groundnuts
At one time some of the countries in Africa were part of the British empire. Now they are independent, but some are members of the Commonwealth of Nations, an organisation that has some of the old British empire countries as members.
large profits from the slave trade
British Commonwealth of Nations
Quite possibly nobody thought in those terms.