Romeo and Juliet is a tragedy because

Romeo and Juliet
Juliet:O serpent heart,hid with a flowering face!
Did ever dragon keep so fair a cave
Beautiful tyrant:Fiend angelical
Dove-feathered raven!wolfish-ravening lamb
Despised substance of divinest show!
A damned saint,an honorable villain!
(From Romeo and Juliet)
Juliet is referring in the above passage to

Romeo and Juliet
"O'Romeo,Romeo!Wherefore art thou Romeo?
Deny thy father and refuse thy father and refuse thy name"
Juliet makes this statement because

'From forth the fatal lions of these two foes
A pair of star-crossed lovers take their life...'
These lines from Romeo and Juliet suggest that the

'O she doth teach the torches to burn bright!
It seems she hangs upon the check of night
As a rich jewel in an Ethiop's ear'
Romeo and Juliet

In these lines Juliet's beauty is presented