Fire requires three essential elements to survive – namely, heat, fuel, and oxygen. The firefighters represented these three essential elements with the help of a triangle. This triangle came to be known as the Fire Triangle.
The fire triangle explains that three elements — heat, fuel, and oxygen — are essential for a fire to start and continue. Heat provides the ignition source, such as sparks from welding or a hot surface. Fuel is any combustible material, like wood, oil, paper, or even leaking LPG. Oxygen, usually from the air, supports the burning process. For example, in a workplace, welding sparks (heat) can ignite oil-soaked rags (fuel) in the presence of air (oxygen). To stop a fire, we remove any one element: cooling with water removes heat, shutting/ closing a fuel valve removes fuel, and covering a fire with a blanket or using CO₂ removes oxygen. This principle helps in both fire prevention and firefighting.
Similarly, at home, leaving a pan of oil unattended on a lit gas stove (heat + fuel) can catch fire when exposed to air. To stop a fire, you can remove any one element: cooling with water (with wetting agent) removes heat, shutting off the gas supply removes fuel, and covering the burning pan with a lid or wet cloth removes oxygen.