Yes; for example (9, 12, 15) can not be found. However, all primitive triples are found.
You cannot.
Sound waves can't be generated in a vacuum.
The triangle concerned MUST be a right-angle triangle. If one of the angles is not 90 degrees, you cannot use the Pythagorean theorem! Also, it must be remembered that the theorem only involves the magnitudes (lengths of the sides), you can't use it on i-j-k vectors or the like, only their magnitudes. As a result, it cannot tell us anything about the directions or angles between lines. Other than that, the Pythagorean theorem is incredibly sound!
Its Formula cannot be obtained because it is a mixture
You can't. It i randomly generated and cannot be changed.
There is no formula for Pi, it cannot be represented by any formula. It is a fundamental constant.
Toothpaste is a mixture, not a compound and so there cannot be a chemical formula.
Toothpaste is a mixture, not a compound and so there cannot be a chemical formula.
AC current cannot be stored, it must be used as it is generated.
NPC villages are currently not in the code for generated structures in Minecraft: Pocket Editon. Therefore they cannot be generated in any seeds in the game, and are only able to be generated in worlds on the PC version.
Since the Pythagorean theorem has 3 variables (the 3 sides), and you only know one variable, you cannot use it to solve for the other 2 variables. Do you know any other information (like angles)? that can be used to solve the triangle (you would not be using the Pythagorean theorem, though). Did they mark the 2 legs with little 'tick marks' denoting that they are equal? Then you could use the Pythagorean theorem because then you know 2 varaibles, and you can solve for the third variable.
No, you cannot delete a bank statement. Once a bank statement is generated, it is a permanent record of your financial transactions and cannot be deleted.