The flag of Mauritania consists of a green field with a yellow (gold) crescent moon and star centered on it. The aspect ratio of the flag is 2:3. The color codes for the flag are as follows:

Green:

• HEX: #006233
• RGB: (0, 98, 51)
• CMYK: (100%, 0%, 48%, 62%)

Yellow (Gold):

• HEX: #FFC61E
• RGB: (255, 198, 30)
• CMYK: (0%, 22%, 88%, 0%)

The geometric properties and measurements of the Mauritania flag are not strictly defined, but some common features include:

1. The width of the crescent is about half the height of the flag.
2. The distance from the tips of the crescent to the center circle forming the star is approximately one-third the height of the flag.
3. The five-pointed star in the center of the crescent has an inscribed circle diameter that's roughly one-sixth the height of the flag.

However, these dimensions may vary slightly depending on the specific version of the flag you are looking at.