Question

why is the climax of the tell tale heart important

Answer 1

@.Sam.

Answer 2

NOTE: This is arguably considered to be the "climax" of the story (I personally think so)

So, at first the narrator is pretty calm and collected when the police first show up. He gives them the guided tour of the house, and then invites them to hang out with him in the man's bedroom. But, the narrator starts to hear a terrible noise, which gets louder and louder, until the narrator can't take it anymore.

NOTE: This is your answer.

Thinking it might make the noise stop, the narrator tells the cops to look under the floorboards.

That is why he tells the cops...he gets so anxious and frightened that he (without giving it any true thought) confesses to the murder.