How do you figure???

[CLL]

I had a man call that wants to cover the ceiling of his gazebo with cedar. Question is how do you figure how many board feet will it take. The gazebo is 14 X 16 and about 6 feet from top of wall to peak. Don't have a clue. help!!

[tomboysawyer]

Is it rectangular or octagonal? (Because I'm not seeing a 14' x 16' octagon...)

When you know two sides of any triangle, you can always calculate the third because a² + b² = c².

If the gable end is on the 16' side, the triangle has one side that is half of that (8') and one side that is 6'.

64 + 36 = 100 and the square root of 100 is 10 (this direction is easy, because that's a 3/4/5 triangle). Then each side of the ceiling is 10' x 14' (times 2). So your total area is 280 sq. ft. As with other threads, any board thinner than 1" still gets sold at the 1" thickness rate, so you have 280 bf of cedar.

The other direction (with the 14' side being the gable end) is a bit tougher math. But any computer has a calculator to do this for you (use the "sqrt" button on your MS calculator).

49+36=85  The square root of 85 is 9.22. Multiply that by 16 and by 2 and you get 295 bf.

If it were me, I'd buy some extra.

[CLL]

Thanks Tomboysawyer, I appreciate the info. Like I said I didn't have a clue.

[Cedarman]

You have to have one 90 degree angle in the triangle for  Pythagorus to get credit. .  Former math teacher.

[DanG]

About halfway through Tomboysawyer's post, I went crosseyed, so I went back and took a quick, holistic view of Brdmkr's doors.  It was awesome! 8) 8)

[fat olde elf]

Looks like DanG might have adult onset attention deficit disorder...He is not old enough to have dementia like us oldtimers......Keep the faith....

[WDH]

About halfway through Tomboysawyer's post, I went crosseyed, so I went back and took a quick, holistic view of Brdmkr's doors.  It was awesome! 8) 8)

Yes, there is no doubt.  By tomorrow, DanG will be espousing the secrets of the Universe to all the Forestry Forum (and anybody else who will listen, except Texans, who don't listen to anyone ;)).

[tomboysawyer]

You have to have one 90 degree angle in the triangle for  Pythagorus to get credit. .  Former math teacher.

touche - my bad for saying "any". It should have been any right angled triangle.

former math whiz

[Tom]

I'm sure glad somebody knows what they are talking about.

Current math idiot :P

[maple flats]

Just have the customer tell you how much he wants, that way his loss from angles cutting producing scrap is his computation problem too. (did I just say what I thought I said?) ;D

[Don P]

I'm still worried about Pythagorus being Cedarman's former math teacher

[WDH]

Maple Flats,

I understood it, but I had to read it three times .

[Cedarman]

He graded hard too.

[pappy]

Yes, there is no doubt.  By tomorrow, DanG will be espousing the secrets of the Universe to all the Forestry Forum

I'm still a waitin' Dang  ;D :D ;D  :D ;D


CLL,
I figuratin approx 350 fbm...  Don't ask me how I know that  : ( ok this is how I did it 14' X 16' and add 50%)  but it sounds like a good start and if he runs out he'll be back...  ;D

Tim the mathly challenged, but I do have a calculator  ;D

[isawlogs]

  Pop_corn  Good thing I have friends that can read english better then me , yep, and then they read it and dont understand any better den me  ;D
I was real good in math ... but it was a whole different typo math .  ;D

[leweee]

 :D Anybody see were I put that tapemeasure ??? :D

[Paschale]

:D Anybody see were I put that tapemeasure ??? :D

That's my biggest math challenge most of the time.    ;D Even when I decide to buy extras, I never can find one.   :

[tomboysawyer]

Thought a picture might help.

Notice that this does not account for any overhang.

CLL knows two sides of the rectangular footing and the hieght of the roof. What he needs is the length of the angled part of the roof.

If you know any two sides of a right-angled triangle, you can calculate the third.
In this case, we know the height of the roof: 6' (the blue dashed line in the picture - or "b")
We also know the length of each end but I don't know which end is the gable end. So I did it both ways. We'll figure the gable end is the 16' dimension, but you can do it any way you want.

Where the 6' peak meets the 16' dimension we are going to assume it meets in the middle. If it doesn't, well, then we have two different rectangular areas. But if it DOES meet in the middle that means that "a" (or the gold line) is 8' (or one half of 16').

Now we need to calculate "c" the hypotenuse of this right angled triangle and we use the Pathagorean theorum (my spelling's not so good tonight).

a² + b² = c²

Squaring something is just multiplying it by itself so that formula looks like this:

( 8 x 8 ) + ( 6 x 6 ) = c²
   64     +  36     = c²
         100          = c²

To figure out "c" we need to take the square root of both sides of the equation. If you don't have a calculator handy, especially with lumber, you can just keep trying multiplying numbers by themselves until you find one close enough. In this case, though, 10 times 10 is exactly 100 so "c" equals 10.

Then to get the area of one side of the roof, you multiply the two sides of the rectangle: 10 x 14 = 140
There are two of 'em so that would be 2 x 140 = 280

Enjoy!!

[SwampDonkey]

You have to have one 90 degree angle in the triangle for  Pythagorus to get credit. .  Former math teacher.

touche - my bad for saying "any". It should have been any right angled triangle.

former math whiz

        ________________________
c = √a² + b² - 2 x a x b x COS(θ)

Dropping the 2 x a x b x COS(θ) is for right triangles, since COS(90°) is 0.



For triangles with two known sides forming a 60° angle at their vertex, the remaining side is:

        ________________________
c = √a² + b² - 2 x a x b x COS(θ)

Since COS(60°) is 1/2 all your left with on the tail of the equation is "- a x b"