
Answer:
         |
         OH
Explanation:
The IUPAC name, 2-hydroxypropanoic acid, lets you predict the structural formula for lactic acid.
Hence, in conclusion the structural form of lactic acid is:
          |
          OH
I used the superscripts just to show the number of the carbon atom in the chain.
The formal structural formula does not contain such superscripts it is just:
         |
         OH
A more developed structural formula will show the distribution of the atoms in the space. I have also attached a picture with the developes structural formula.