Step-by-step explanation: The international standard symbol for inch is in (see ISO 31-1, Annex A) but traditionally the distance is denoted by a double prime, which is often approximated by double quotes, and the foot by a prime, which is often approximated by an apostrophe. For example, three feet two inches can be written as 3′ 2″. Symbol: in or ″ (the double prime)
