The Triforce is an item used in The Legend of Zelda series. It is a holy relic created by the goddesses. It is a golden item that has three seperate triangles, each with a name - The Triforce of Power, Triforce of Wisdom, and the Triforce of Courage. Anyone who touches it has all their wishes granted.
If one with a good heart makes contact, Hyrule will be plunged into an age of prosperity, but if one with an evil heart touches it, the land will plunge into darkness. Eventually, Link obtains the Triforce of Courage, Ganondorf obtains the Triforce of Power, and Zelda obtains the Triforce of Wisdom.
There was absolutely nothing. In time, though, three goddesses appeared from a nebula near what would soon become Hyrule. The three goddesses that made this triforce are the three creators of Hyrule: Din, Farore, and Nayru. After the goddesses made the world of Hyrule, they made the Triforce which created magic and balance in this world. The three goddesses then returned to the skies.
Occasionally during special events, Google.com will feature a special logo to celebrate something such as special anniversaries or advancements in technology or science. On four occasions, Google has hidden a Triforce in these logos - one on Thanksgiving 2008, one on Halloween 2009, one on April 22, 2009 (Earth Day) and one on July 10, 2009 (Nikola Tesla's birthday, although he had been dead since the early forties). The images can be seen below:
For the Triforce in this image, look between the 'G' and the 'o' in the dirt.
For the Triforce in this image, the Triforce is below the Knife's handle in the middle.
For the Triforce in the image above, look in between the 'G' and the 'o' and go all the way down.
For the Triforce in the image above, look in between the 'l' and the 'e'.