How many isomers can be drawn (constitutional and stereoisomers) for dimethylcyclopropane in which the cyclopropane remains intact

Achemist reacted 57.50 grams of sodium metal with an excess amount of chlorine gas. the chemical reaction that occurred is shown. na + cl2 → nacl if the percentage yield of the reaction is 86%, what is the actual yield? show your work, including the use of stoichiometric calculations and conversion factors.