Is Rigatoni similar to Penne Pasta?

Yes it is, but penne is narrower and has diagonal cuts on the ends. Riggitoni is bigger around and has blunt ends.

Rigatoni has grooves or cuts if you will all around the outside.... in fact "rigato" in Italian (also) means scratched or scored. Penne are smooth.

Both can be the same shape or even size but it's the texture that differentiates them.

In theory the rigatoni holds your sauces better.

yes they are similar but yet they are different,rigatoni is lager and flat at the edges while pene is smaller and are cut at an angle at the edges both are striated