explain how victor is similiar to a tragic hero?

The most obvious way may be invisible: genre. The classic tragic hero is found in a stage play; Frankenstein is found in a novel. This matters because his actions are filtered more for us than a character's on stage would be (remember the letter format?). However, after that one important thing is that his family had already fallen in the world (remember the start of Chapter 1?). Rather than being on top of the world, as is, say, Othello or Oedipus, Frankenstein's got something to prove.