TRIVIAL PURSUITS: Which countries’ flags are not rectangular?

Can you name the three that are not?

Answer: Nepal’s flag is two overlapping right triangles. The smaller, upper triangle bears a stylized moon, and the larger, lower triangle contains a 12-pointed sun.

Switzerland and the Vatican City are the only two countries with square flags. Though squares are, technically, rectangles, a square is not the shape that comes to mind when talking about rectangles.