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does anyone know how to work out the volume of my fish tank. I need the formula to work out a triangle shape.

Thanks

Cant find it anywhere on the net,

Dawn

If it is shaped like a prism, then it's just area of the base x height.

thanks for the reply sorry to sound realy thick but how do i work out the area for instance..


on of the triangle is 83cm by 83cm by 118 cm and depth is 60 cm so how do i work that out?

thanks
Dawn

That works out to 206658.4 cubic centimeters, I think.

This would be about 206.7 liters.

1/2 * b* h = area of triangle

b=118

h=((82)**2 + (118/2)**2))**1/2 = 101.01

=> 357540 cm**3

Sorry still confused, I have to be right as we treating the tank for disease (this is only part of the tank as due to its shape we had to brak it down into triangles and rectangles, we are ok with the latter)

D

Actually, the correct h should be

((82)**2 - (118/2)**2))**1/2 = 58.38 (using Pythagoras' theorem to calculate the height of the triangle)

Volume should then be (58.38 x 118)/2 x 60.

Thanks for your help so far, please could you tell me the volume in litre.

plus the same for the next triangle which is 22 x 22 x 28cm.

Thanks

D

As I mentioned earlier, that works out to 206.7 liters.

The area of the second triangle is about 237.6 square centimeters. Multiply that by the height of the tank (in cm) and divide the total you get by 1000 to get the volume in liters.

Silurus wrote: Volume should then be (58.38 x 118)/2 x 60.

I would check the 58.38?

Hiya yes i have checked the 58.38 and that seems about right...i worked the other one out at 14.256 is that right?

Thanks sooo much for this its such a help.

Dawn

mitmop wrote:Hiya yes i have checked the 58.38 and that seems about right...i worked the other one out at 14.256 is that right?

Thanks sooo much for this its such a help.

Dawn

Yes, I noticed the error (negative) on my calculation of 101.
Assumming the height (60) is the same:
Vol = 1/2* 28 * 16.9 * 60 = 14196

The height of the second triangle actually works out to 16.97.

((22)**2 - (28/2)**2))**1/2=16.97

Thankyou very much for your help you are a life saver I have worked out the tank is about 365 ltr in all.

Thanks again.

Dawn

The tank sounds like a trigon 350. In jewel tanks the number indicates the litres, Just some info for future use. Save time in the calculation stakes

Everybody is overcomplicating things

83x83x118, surely thats a right angle triangle, therefore:

(83*83)/2 = Area of base = 3444.5cm2
3444.5 * 60 = Volume of tank = 206670cm3
In litres /1000 = 206.7litres

Should havd been a maths teacher, you there quite at the back..... Are you chewing! Oh the power

Owch wrote:
83x83x118, surely thats a right angle triangle, therefore:

Actually, two equal side does not imply square.
118**2 = 13924

83**2 + 83**2 = 13778

Not square. BTW, I didn't read the original post close enough and used 82 rather than 83.

I figured that a tank with 2 equal sides was going to be a corner tank , anyway, I dont think anyone is going to want a tank with an internal angle of 90.607degrees

But your method doesn't work so well for 22 X 22 X 28.

zenyfish wrote:But your method doesn't work so well for 22 X 22 X 28.

Its not my method, some guy called Pythagoras made it up

22*22*28 would have 2 equal angles of 50.48deg and 1 of 79.04deg (2dp). And a height of 16.97 (2dp)

Owch wrote: Its not my method, some guy called Pythagoras made it up

I'm referring to assumming 90 degrees?

zenyfish wrote:

Owch wrote: Its not my method, some guy called Pythagoras made it up

I'm referring to assumming 90 degrees?

Well then 22*22*28 cannot be a 90deg triangle

Owch wrote: (83*83)/2 = Area of base = 3444.5cm2

Its not my method, some guy called Pythagoras made it up

I'm afraid I don't see Pythagoras here.

So if it looks close to 90, you'll assume 90? What's the cutoff? At 87, 86, 85? 93, 94, 95?

Things are getting a little out of hand here, like I said earlier, 'overcomplicating things'.

No cut off, just a rough estimate of this ladys tank volume, and I figured the method I used to be fairly accurate, and VERY simple.

And as for looking close to 90deg, well 83*83*118 dimensions of a triangle gives 1 internal angle of 90.6...... and 2 equal internal angles of 44.7, sorry for being pedantic, but thats as near as damn it a right angle triangel

Owch wrote:but thats as near as damn it a right angle triangel

Yes, I agree it probably was 90 and her measurement were off a bit or rounded.

But without actually seeing the tank or sketching it out, I would not have assume it.

But you were forced to use 'overcomplicating things' for 22 X 22 X 28?

Your point to this whole debate

I cant see one.

Owch wrote:I figured that a tank with 2 equal sides was going to be a corner tank

I would not assume 90, it was coincidental in the case of 83 X 83 X 118. But not so in the case of 22 X 22 X 28.

Maybe you have a better sense of porportions, I cannot look at the numbers 83 X 83 X 118 and say "Oh, that's a right triangle!" How do you know? Is 80 X 80 X 123 a right triangle for instance?

Your method is estimated, subjective, and specific. It relies on what looks like 90 and and only for angles close to it. The method I used is general and works for all cases.

I would argue your method is more 'overcomplicating' since it's subjective. So maybe I used a method not so 'overcomplicating'? I mean, you had to use it also, true?

OK, this is the Speak Easy forum, but I believe that this post has long outlived its usefulness.

Geometry lesson's over, folks.