Your question is poorly worded and there is no way to tell what you want to know.
That would depend on the make and model of the shotgun in question,and the length of the barrel/barrels that came with the shotgun.
A little over 36"
@ 40" or so depending on LOP and Barrel length.
18 inches and a total overall length of at least 26 inches, just like in the rest of the US.
A barrel no shorter than 18 inches in length. The overal total length of the firearm cannnot be less than 26 inches from the tip of the muzzle to the end of the buttstock.
From the breech.
From the breech
Any shotgun with a barrel length of less than 18 inches and/or an overall length of less than 26 inches.
A shotgun is a shotgun, regardless of what you do to it (except should its length go below certain limits, it will be reclassified as a pistol or handgun in some jurisdictions). If you saw some of it off, then it becomes a "sawn-off shotgun", pending the above restriction on length.
18.5 inches
18"
From the muzzle to the end of the buttstock.