How many gallons is this octagon?

[Day13]

25" tall and about 21" at it's widest. Believe it's either 29, 30, or 36 gal. I would rather not fill it a gallon at a time. So anyone know offhand, or a better way to fill it so I can tell myself? Thanks a ton.

 

[ravio11i]

http://www.easycalculation.com/area/prism.php
this has wizards for finding volumes of various prisms, (your hex tank is a hexagonal prism)

The Apothem Length is the length from the middle to a corner, probably easiest measured from corner to corner then divide by two.
This assumes all your sides are the same length.
If you use inches for your measurements you will get a volume in cubic inches, just divide this by 231 to get your volume.

Rav

 

[ravio11i]

oops misread didn't see yours was an octogon.
sry

 

[ravio11i]

can you say post count, now I've got it. area of an octagon is figured by 2*length of side*dist between parallel sides. volume is area*height. once again if you do the math in inches you will get an answer in cubic inches just devide by 231 for gallons.
Rav
once again this assumes all sides are the same.

 

[dct3416]

It's roughly 36 gallons.

 

[MadRussian79]

I'm getting 33 gallons and 8" sides.

 

[Day13]

You're right Rav it's a hex. Never dawned on me, was just taking the persons word I got it from.
Thanks to your link and explanation of apothem, i'm looking at 34 gallons. Thank you both for the help.

 

[packer43064]

I have a 35 hex. It's probably the same as mine then.

 

[Day13]

sounds right, 35, I was quick on measuring, thanks

 

[texasguy]

Apothem is center to the middle of a side. Radius is center to corner. ravio i think you got them mixed up