pennant
Interstate highways are usually identified on shield shaped signs.
Ohio is the U.S state with a pennant-shaped flag
Signs which denote Interstate Highways are red, white, and blue.
The flag of Nepal is shaped like two triangles, one above the other like a cavalry pennant.
C
means no passing zone
I'd say the one that looks like a triangle.
Yes, stop signs are octagonal in shape.
Interstate highway
Shaped like an X
Nepal's flag is shaped like a triangle fixed on top of another triangle. See Sources and related links for a picture.A square is a type of a rectangle. Hence, the square-shaped flag of Vatican City State and Switzerland are types of a rectangular flags.