π is an irrational number because pi is a repeating decimal (YES)
Also, it cannot be represented as a fraction.
✓ 7 is irrational because 7 is not a perfect square. (YEs)
✓ 7 is not a perfect square = 2.645751311 and irrational
7.1234... is irrational because it is a nonterminating, nonrepeating decimal (YES)
nonterminating, nonrepeating decimal numbers cannot be represented as fractions, so they are irrational.