The fire triangle concept states that fire needs three elements to live. The elements of the fire triangle are: Heat Fuel Oxygen Firefighters use the fire triangle to extinguish fires. If one of the elements of that create fire are removed, they fire will die. Here are some examples. A fire involving wood can be extinguished with the heat removing effect of water. A wild land fire can be extinguished by removing fuels such as shrubs, grass, or trees. A kitchen grease fire can be extinguished by removing the oxygen when a lid is placed over the skillet or ppan.