What are the molecules (monomers) that build polysaccharides,proteins and lipids?

monosaccharides
amino acid
triglycerol and fatty acid chains

polysaccharides,- monosaccharides
proteins - Amino acids
 lipids don't have a monomer. They are polymers of fatty acids and glycerol in ration of 3 : 1.

Polysaccharides are another fancy word for complex carbohydrates. So a molecule such as glycogen, cellulose, and maltose would be polysaccharides. Technically, multiples of monasaccharides build up polysaccharides. So if we have a long chain of glucose molecules, they form a chain covalently bonded by glycosidic linkages.

The monomers of a protein would be amino acids. There are 20 known amino acids, each forming a different combinations of protein chain. Just for your information, a long chain of amino acid is called a polypeptide chain, each covalently bonded by peptide bonds.

Now lipids can get confusing. The most commonly known complex lipid is called a triglyceride, which is composed of a glycerol head and three fatty acid tails. Depending on the type of lipid you are looking at, there can be a variety of fatty acid tails. For example, phospolipid (the ones that make up the cell membrance) has one glycerol, one phosphate head, and two fattly acid tails.

Now just for your own information, there is a fourth macromolecule called nucleic acid. The monomer for nucleic acid would be nucleotides. The two common types of nucleic acids are DNA and RNA. Both of these can branch out into different types, depending on where they function. For example, mRNA is a type of RNA that carries DNA messages towards the protein site.