How to create this part using PATTERNS

If it still works like back when I was using Pro-E, it's pretty easy as it allows you to select multiple dimensions to use to drive a pattern. Your example would use 1)the dimension locating the peg vertically on the cylinder, 2)the diameter of the peg, and 3)the tricky one, you'll need to make sure there's an angular locating dimension to the peg.

See
I may explain you in CATIA.
You can use the user-defined pattern for the array
also the pattern must be the helix
and you may create equidistant points on that helix before selecting user-defined pattern.
Hope it helps you