The analysis is simple. If we can draw a line drawing from the intersection, and then find the point whose distance to the other side of the library is equal to the distance from the first intersection to the library, then this problem can be transformed into an encounter problem, and the intersection distance is equal to twice the distance from the first intersection to the library. Calculate the meeting time and multiply it by my brother's speed to know how far it is from the library.

Meeting time: (4.8-1.2) x1000x2÷ (240+60) = 24 minutes.

(4.8- 1.2)x 1000-24x 60 = 2 160

Then the distance from the second meeting point to the library is 2 160m.