Three kids - find their ages

Jack and Jill were childhood friends. They meets after several years.

Jack: How many kids have you got?
Jill: Three kids. Product of their ages is 72 and sum of their ages is same as your birth date.
Jack: I still did not get their ages.
Jill: My eldest son started going for piano classes.
Jack: Now I got their ages.

What are the ages of Jill's kids?

Click here to find the solution