With a flag dimension ratio of 2:3 height to width, which country’s flag is this?

The Indonesian flag is a horizontal bicolour with 2 equal horizontal bars of red and white. The dimensions of the flag are in the ratio of 2:3, height to width.

In Indonesian, this flag is called "Sang Saka Merah Putih" ("lofty bicolour red and white"). The red symbolizes human blood and the white represents the human spirit.

The flag of Monaco is graphically identical to the flag of Indonesia, with a difference in its dimension ratio, Monaco's at 4:5 and Indonesia's at 2:3. The shade of red also differs. The flag of Poland has the colours reversed with white on top and red on the bottom.

Indonesia's flag was first associated with the Majapahit empire, which flourished from the 13th to the 16th century in eastern Java, and it incorporates traditional colour symbolism. More recently, it was adopted in 1922 by the Indonesian Union, a nationalist organization of Indonesian students studying in the Netherlands. In 1928 the Indonesian Nationalist Party also adopted the flag.

The Indonesian flag was officially adopted on August 17, 1945, 3 days after the conclusion of World War II. It remained the national flag when Indonesia gained its independence from the Netherlands in 1949. The flag featured in a well-known incident which occurred in the lead-up to the Battle of Surabaya in 1945. Indonesian youths removed a colonial Dutch flag flying over the Yamato Hotel. They tore off the blue strip and re-hoisted it as an Indonesian flag.