Final answer:
Macduff announces King Duncan's murder in Shakespeare's play Macbeth.
Step-by-step explanation:
In William Shakespeare's play Macbeth, it is Macduff who announces that King Duncan has been murdered after finding his body. This is a pivotal event in the play that sets off a chain of tragic events, leading to Macbeth's own downfall. Macduff's discovery and announcement of the king's death is a turning point that underscores the themes of betrayal and the consequences of unchecked ambition.
The person who announces that Duncan has been murdered after finding his body is Macbeth.