How do you write a paper using the common topic of definition?

I have to write two papers using the common topic of definition. in the first i have to discuss the hero qualities of three knights. beowulf, sir gawain, and the knight from the canterbury tales. in the second still using the common topic of definition and symbolism, have to do it on two paintings the arnolfini wedding and saint jerome in his study and discuss which picture we think symbolizes more or something if that makes any sense.