A pie graph is the graph used to show how a part of something relates to the whole.
Haze is caused by particulate matter from incomplete combustion of car, truck, bus, burning of gasoline and diesel. This could also be caused by the buning of wood, coal, and heating oils from industry, electical generation plants that do not collect some of the pollutants at the smoke stack or exhaust points.
This is the answer hope it helps you!!