how does routing work with LANs connected on WAN links?

Problem Statement:

A network is being planned with three sites, New York, Westchester; and Long Island. New York has 40 hosts, Long Island and Westchester each have 10. There will be WAN links between New York and Westchester, Long Island and Westchester, and New York and Long Island. You have been assigned a class "C" address space of 10.1.1.0/24. Divide the address space accordingly so that you have room for expansion and so that you do not excessively waste addresses where they will never be used. Each router has three network interfaces, please list the P and subnet mask (in CIDR notation; i.e. 10.1.10.0/24) for each one. Provide the complete routing table for the New York router.

Confused as to how the addressing is going to work with the routers, is each going to have 2 IP addresses, a LAN facing one and a WAN facing one? are the WAN facing addresses on the same subnet?