Lin and Han ran a 5 miles relay race.
If they both ran same distance, that means each of them ran;
So, Lin and Han ran 2.5miles each.
The diadramatic representation of this scenario is;
The image above shows a track race of 5 miles divided into two. LIN ran half of it (2.5 miles) and also Han ran the other half, also (2.5 miles)