Consider the following theorem and proof Theorem Theorem The
     Consider the following theorem and proof Theorem.  Theorem: There are infinitely many primes.  suppose there exists only finitely many primes p_1  
  
  Solution
The basic structure is proof contradiction.
Because we start the proof by assuming there are finitely many primes and we end up with a thing that a prime number divides 1 which is not possible i.e. a contradiction.
The basic idea behind proof by contradiction is, DENIAL OF THE STATEMENT BEING PROVED RESULTS IN A CONTRADICTION.
Here we denied the statement that there are infinitely many primes and end up with a contradiction.

