What is triangle film?

As an AI language model, I do not have information about any specific triangle film as there could be many movies named after triangles or reference triangles in their storyline. However, there is a 2009 British horror film called "Triangle" directed by Christopher Smith. The plot of the film revolves around Jess, a single mother, who goes on a yacht trip with a group of friends but finds themselves caught in a mysterious Bermuda Triangle-like storm that leads to a series of strange events and terrorizing occurrences. The film explores themes of time loops, psychological horror, and the questioning of reality. It received mixed reviews from critics but has since gained a cult following.