Triangle Island

In The Wind Waker, the Triangle Islands, also sometimes known as the Triangle Isles, are three islands shaped like triangles, and also in such a formation in the sea that if one were to draw lines connecting them, the result would also be a triangle. They serve the purpose of holding three statues of the goddesses, and one of three different pearls that correspond to the goddesses can be placed in their arms. This is the key to raising the Tower of the Gods that Link must enter during his quest across the Great Sea.

When lines are drawn between the three Triangle Islands, a giant triangle is formed with the Tower of the Gods in the center. Likewise, if lines are drawn between the initial resting places of the pearls (Greatfish Isle, Dragon Roost Island, and Forest Haven), another triangle is drawn. Overlaying these two triangles creates the image of the Triforce with the Tower of the Gods in center. In the inner triangle, Din's statue will form the top corner, Nayru's the left corner, and Farore's the right corner. These are also the locations of their respective pieces on the Triforce

Eastern Triangle Island
Eastern Triangle Island has the statue of Farore, which requires that Farore's Pearl must be placed on it for activation.

Southern Triangle Island
Southern Triangle Island has the statue of Nayru, and as such, Nayru's Pearl must be placed within its arms. Link can also retrieve Triforce Shard #6 from the ocean floor after obtaining the Triforce Chart from Outset Island.

Northern Triangle Isle
Northern Triangle Isle has the statue of Din, upon which Din's Pearl must be placed. Link can also use the Treasure Chart he received from the Six-Eye Reef to obtain the Big Octo Chart here. It is one of the islands, along with Shark Island and Mother and Child Isles, where cyclones rage before Link chastises Cyclos.

Trivia
It has been noted by some members of the community that the positions of the Triangle Isles are similar to the positions of the three temples that housed the Pendants of Virtue in A Link to the Past. For example, the Eastern Triangle Isle is similarly placed to the Eastern Palace in A Link to the Past, which held the Pendant of Courage, the attribute Farore is associated with.