What does the fire triangle illustrate as essential for fire?

The fire triangle illustrates the three essential components required for fire to ignite and sustain combustion: oxygen, fuel, and heat.

Oxygen is necessary because it supports the chemical reaction that occurs during combustion. Without enough oxygen, a fire cannot burn. Fuel is any material that can burn, such as wood, paper, or gasoline, providing the substance for the fire to consume. Heat is the energy source that raises the temperature of the fuel to its ignition point, enabling the combustion process to begin.

When these three elements are present in the right proportions, a fire can start and continue to burn. If any component is removed or reduced, the fire will extinguish or be unable to ignite. This concept is crucial for understanding fire behavior and for fire prevention and firefighting strategies, demonstrating the interdependence of these elements in the fire triangle.