Question

what is a postulate? give an example​

Answer 1

A postulate (also sometimes called an axiom) is a statement that is agreed by everyone to be correct. This is useful for creating proofs in mathematics and science, and postulates are often the basic truth of a much larger theory or law.

Postulates themselves cannot be proven, but since they are usually obviously correct this is not a problem. Here is a good example of a postulate (given by Euclid in his studies about geometry).