ductwork connections question

[vic]

I'm putting together 3.25x10 a/c galvanized dust work

I'm having a little difficulty connecting the straight stacks to the elbow fittings.

As I have found it takes some manual dexterity to attach the fittings, I'm wondering if I'm doing it right.

Does the assembed two piece rectangular stack runs go inside the elbow connectors OR do the ends of the metal elbow connectors insert inside the rectangular straight stack ???

Thanks for your help!

[3G]

all depends on the direction of the air flow male into female in way of air flow.

[deke]

Send pictures.