Problem $2(40$ pts$)$ Our team has been contracted by the PennDOT to design a three$-$span overpass. To design the bridge, we want to find the peak positive and negative moment based on the unfactored dead load.

$(1)$ Check the determinacy for this problem. $(10$ pts$)$

$(2)$ Choose the proper redundants for this problem. $(10$ pts$)$

$(3)$ Set up the compatibility equations using force method for this problem $($Note: there is no need to solve this problem$).(20$ pts$)$