Answer:
the prologue helps discern the play is a tragedy because:
1 ) it uses the phrase "star crossed lovers" which literally means lovers whose love is agianst the stars. This tells the audience that people and/or situation does not favour these lovers.
2) a tragedy is truly tragic if it doesn't start of as bad. With the introduction of romance followed immediately by the prediction of their death.
3) another element of a true tragedy is reversal of fortunes after the protagonists' demise or downfall. We were informed about the feud between their famillies, which must hav been why they were star crossed lovers, and the fact that the famillies feud was put to an end by their children's death tells us the play is a tragedy.
