Where in the world?
The flag of South Sudan has three horizontal stripes of black, white, red, and green with a blue triangle on the left side containing a yellow star.

South Sudan

Population: 11,193,729

Region: Africa

Subregion: Middle Africa

Capital: Juba

Top Level Domain: .ss

Currencies: South Sudanese pound

Border countries

The flag of the Central African Republic has four horizontal stripes of blue, white, green, and yellow with a red vertical stripe in the center and a yellow five-pointed star in the upper hoist-side corner.

Central African Republic

Population: 4,829,764

Region: Africa

Capital: Bangui
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 Ethiopia has three horizontal stripes of green, yellow, and red with a blue circle and a yellow star in the center.

Ethiopia

Population: 114,963,583

Region: Africa

Capital: Addis Ababa
The flag of Kenya has three horizontal stripes of black, red, and green, separated by white edges, with a red, white, and black Maasai shield and two crossed spears in the center.

Kenya

Population: 53,771,300

Region: Africa

Capital: Nairobi
The flag of Sudan has three horizontal stripes of red, white, and black with a green triangle on the left side.

Sudan

Population: 43,849,269

Region: Africa

Capital: Khartoum
The flag of Uganda has six horizontal stripes of black, yellow, and red with a white circle in the center containing a grey crowned crane.

Uganda

Population: 45,741,000

Region: Africa

Capital: Kampala