When the clothes are exposed to heat then the water molecules in the escapes so the clothes becomes dry
By the phenomenon of evaporation .. u may hav noticed that whenever you boil water its level decreases because the water evaporates in the form of water vapours same is the case while drying clothes due to the heat from the sun the water evaporates from the cloth and secondly due ti wind speed .. on a windy day clothes dry fast because the vapours are blown away by the wind and thirdly due to more surface area as we spread the clothes their surface area increases and evaporation takes place at high speed