Answer:
These lines are an example of a metaphor.
Step-by-step explanation:
These words that Lord Capulet says when seeing his daughter dead, refer to death figuratively through the use of a metaphor.
It is important that we do not confuse metaphor with simile, since it is very common for us to be confused because they are very similar. The difference is that a simile compares two things using words like "like" or "as". In a metaphor, two things are compared but without the use of those words.
There is a more implicit connection where an attempt is made to make a deeper and meaningful comparison.
In this case we have phrases like Juliet "has married death" or "death is my heir". When what the author wanted to say was: "my daughter is dead" and "I will have no heirs".