Which reaction is responsible for the production of lipids, when glycerol is joined to three fatty acids

Hydrolysis Lipids consist of glycerol and fatty acids and are constructed from fats, oils, waxes, phospholipids and steroids.
A lipid's function is to insulate the body and provide warmth in cold conditions.
It can be concluded that a person with very little body fat gets very cold easily and a person with a lot of body fat gets very warm very quickly.
Approximately 20-80% of the cell membrane is composed of lipids, the rest, is made up of protein