Where in the world?
The flag of Angola has two horizontal bands of red and black with a yellow half gear wheel crossed by a machete and crowned with a star.

Angola

Population: 32,866,268

Region: Africa

Subregion: Middle Africa

Capital: Luanda

Top Level Domain: .ao

Currencies: Angolan kwanza

Border countries

The flag of the Congo has a green field with a yellow diagonal stripe from the lower hoist-side to the upper fly-side.

Congo

Population: 5,518,092

Region: Africa

Capital: Brazzaville
The flag of the Democratic Republic of the Congo has a sky blue field with a yellow star in the upper hoist-side corner and a diagonal red stripe with a thin yellow border from the lower hoist-side to the upper fly-side.

Congo (Democratic Republic of the)

Population: 89,561,404

Region: Africa

Capital: Kinshasa
The flag of Zambia has a green field with an orange eagle in flight over a rectangular block of three vertical stripes of red, black, and orange in the lower right corner.

Zambia

Population: 18,383,956

Region: Africa

Capital: Lusaka
The flag of Namibia has a diagonal tricolor of blue, red, and green with white fimbriations, and a gold sun with 12 triangular rays in the canton.

Namibia

Population: 2,540,916

Region: Africa

Capital: Windhoek