The fire triangle or ″fire diamond″ are simple models for understanding the necessary ingredients for most fires
The triangle illustrates the three elements a fire needs to ignite: heat, fuel and oxygen. A fire naturally occurs when the elements are present and combined in the right mixture, meaning that fire is actually an event rather than a thing. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle. For example, covering a fire with a fire blanket removes the oxygen part of the triangle and can extinguish a fire but in large fires where firefighters are called in, decreasing the amount of oxygen is not usually an option because there is no effective way to make that happen in an extended area.