Which African country's flag features a green triangle on the hoist side next to three horizontal stripes of red, white, and black? Sudan. The flag combines a green triangle at the hoist with a horizontal red-white-black triband.
Sudan adopted this design on 20 May 1970, replacing the blue-yellow-green flag used after independence in 1956. Its colours belong to the broader Pan-Arab colour tradition, which became especially prominent in flags influenced by the Arab Liberation movement after the Egyptian Revolution of 1952.
The green triangle distinguishes Sudan's version of the red, white, and black arrangement. Green is often associated with Islam, agriculture, and the country's fertile regions, while the three horizontal colours carry historical and political meanings that have been interpreted in different ways. The main mix-up is with Palestine or Jordan: those flags also use Pan-Arab colours, but their hoist-side shapes and stripe arrangements differ. Kuwait likewise has a black trapezoid rather than Sudan's green triangle.