Is it permissible for a person to shave the hair on their legs if it grows excessively?

Your question about something whose ruling you do not know is not a mockery. Hair is divided into three categories: hair that is commanded to be removed, such as pubic hair and armpit hair; hair that is commanded to be left, such as a man's beard; and hair about which the religious texts are silent, concerning which no specific ruling has been revealed. The ruling for this is permissibility; if you wish, you may leave it, and if you wish, you may remove it, and there is no sin.