Shipping with odd size boxes

[beerman_1001]

I ordered some of those USPS triangle shaped boxes-I think they make 2 and I have some of both sizes. 

Havent used any, but am going to sell some items that I think these would be perfect for. 

How do I enter the size of the box, when I go to use them, since EBay's shipping (where you enter the boxes' dimensions) assumes a rectangular package???

TIA. 

[nobody*s_perfect]

It doesn't matter, since the size of those boxes won't affect the shipping cost: They both have a length-plus-girth under 84 inches and a volume under 1 cubic foot.  Just enter the length and two of the sides.

[alcoforever]

If they are Priority Mail boxes, you don't need dimensions, only weight.

If not PM, enter dimensions as if they were a tube.

[a*river*runs*through*it · Accepted solution]

The Small tube is: 25" x 6" x 6"

The Medium tube is: 38" x 7" x 6"