The symbols on the white triangle of the Philippine flag are an eight rayed sun and three stars in gold. The sun represents the dawning of a new era of self determination that was desired in 1897 (when the flag was first designed) after the Spanish-American war and the US promise of independence, which was granted in 1946.
The 8 rays on the sun stand for the 8 provinces that rose in revolt against Spanish rule in the late 19th century. The 3 stars stand for the 3 principal geographic areas of the country, Luzon, the Visayas and Mindanao. To complete the symbolism of the flag, the red stripe represents courage and bravery and the blue stripe is for noble ideals.
The white triangle stands for the Katipunan, a revolutionary organization that led the revolt against Spain and the color white represents peace and purity. This flag is unique in that in peacetime, the blue stripe is uppermost but during wartime, the red stripe is on top. Ref: Smith 1976