The flag of Fiji has an aspect ratio of 1:2. It predominantly consists of a light blue background with the color code #002868. On the upper hoist-side corner, there is a Union Jack (British flag) featuring red (#C8102E) and white (#FFFFFF) colors.

To the right of the Union Jack, on the fly side of the flag, there's the Fijian coat of arms. The shield in the coat of arms features multiple colors, including red (#C8102E), yellow (#FFC72C), white (#FFFFFF), and black (#000000). Surrounding the shield are additional elements in green (#007A33) and brown (#7D4918).

For specific measurements and geometric properties, the flag can be separated into three main parts:

1. Upper hoist-side corner (Union Jack): It occupies a quarter of the flag, with dimensions being 1/2 of the flag's height and 1/4 of its length.
2. Light blue field: This area surrounds the Union Jack and covers the remaining 3/4 of the length.
3. Coat of arms: Located on the fly side of the flag, it's centered between the top and bottom edges in the middle of the light blue field, occupying about 3/5 of the flag's height.

Please note that precise geometric details and measurements of the coat of arms may vary due to its complex design.