Which of the following is NOT a method used to extinguish fires?

Adding fuel is not a method used to extinguish fires. Instead, extinguishment strategies focus on eliminating at least one of the components of the fire triangle: heat, fuel, and oxygen. By removing heat, cooling a fire with water or other extinguishing agents decreases its temperature, making it unable to sustain combustion. Removing oxygen can be achieved through methods such as smothering a fire with foam or using fire blankets, denying the flames the air they need to continue burning. Thus, adding fuel would actually serve to propagate the fire rather than extinguish it, making it distinctly opposite to the methods used to put out fires. Understanding the fire triangle is essential in firefighting, as targeting one of the elements effectively reduces the fire's ability to burn.