The flag of Samoa consists of a red field with a white equilateral triangle based on the hoist side, bearing a red five-pointed star within a blue rectangle. The aspect ratio of the flag is 1:2.

Colors:

1. Red (Pantone 186 C): #CE1126
2. White: #FFFFFF
3. Blue (Pantone 280 C): #002868

Geometric properties and measurements:

1. The equilateral triangle's sides are equal to half the flag's width.
2. The blue rectangle's width is equal to the triangle's base, and its height is equal to one-fifth of the flag's length.
3. The red five-pointed star is centered in the blue rectangle, with each point touching the rectangle's edges.

These are the main features of the Samoan flag without discussing its symbolism.