What are all the methods of proof

And if your theorem is false, then any theorems that come after it and use it might be false too.Like how one misplaced beam can bring down the whole house.So that's all that proofs are:using well-established rules to prove beyond a doubt that some theorem is true.Then you use those theorems like blocks to build mathematics.Let's check out an example.Say I want to prove that these two triangles are the same size and shape.In other words, they are congruent.Well, one way to do that is to write a proof that shows that all three sides of one triangle are congruent to all three sides of the other triangle.