pi≈3.14 so double that is 2pi≈6.28 that's beteween 5 an d7
so an irrational number between 5 and 7 is 2pi
we could also do remember that square roots of non-perfece square numbers are usually irraitonal 5²=25 7²=49 so an irrational number could be √c where 25<c<49 example, √40