What is the name of a pyramid with curved or elliptical sides (think sagging circus tent)? More importantly, how would one calculate the curved sides to show one facet of it in 2 dimensions? I have searched every possible search engine and can not find what it's called and how to draw it. Thanks!
What is this shape called?
- Thread starter sbaarstad
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mmm4444bot
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All four sides of The Great Pyramid are concave. (I didn't know that.)
So, what is meant by, "show one facet of it in 2 dimensions" ?
Are you talking about some sort of cross-sectional view ?
Are you talking about a specific pyramid (for which you have information), or are you thinking of designing one?
It seems to me that there are many such pyramids, depending upon the "degree" of concavity.
Oh, and what about the base. Is the base caved-inward, as well?
So, what is meant by, "show one facet of it in 2 dimensions" ?
Are you talking about some sort of cross-sectional view ?
Are you talking about a specific pyramid (for which you have information), or are you thinking of designing one?
It seems to me that there are many such pyramids, depending upon the "degree" of concavity.
Oh, and what about the base. Is the base caved-inward, as well?
OK... here's what I'm looking for... note the roof shape...[attachment=0:3nv5t1xc]Cabana tent.jpg[/attachment:3nv5t1xc]
Notice how each facet (panel) is not a triangle but rather something with 2 arc or ellipse segments. By varying the ellipse, it could become pointier. So the question is how would one layout this to cut the fabric to make 1 of the 4 panels (hence my question about going to 2 dimensions. Ooohh... and what if the base is a hexagon or octagon, rather than a square as in the picture? Thanks again guys!
Notice how each facet (panel) is not a triangle but rather something with 2 arc or ellipse segments. By varying the ellipse, it could become pointier. So the question is how would one layout this to cut the fabric to make 1 of the 4 panels (hence my question about going to 2 dimensions. Ooohh... and what if the base is a hexagon or octagon, rather than a square as in the picture? Thanks again guys!
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tutor_joel
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So, this is a practical question. How are your math skills? Can you graph an equation like y = 1/x?
Because this general shape might have a name, but it can be defined mathematically by a similar equation. Try graphing y = 1/(30x) with the x and y coordinate window at +/-0.5. You can mess with the 30 number to change the "sag" of the shape. once you find the shape, you can make a fabric size Cartesian system and go at it.
You will need to pick a shape that has the same delta y as your tent. you need to measure what the tip of the pole vertical height to the wall height. Also you will need the distance from the pole base to the wall for your x component.
Your Cartesian window to plot this equation will be fixed at that geometry.
Because this general shape might have a name, but it can be defined mathematically by a similar equation. Try graphing y = 1/(30x) with the x and y coordinate window at +/-0.5. You can mess with the 30 number to change the "sag" of the shape. once you find the shape, you can make a fabric size Cartesian system and go at it.
You will need to pick a shape that has the same delta y as your tent. you need to measure what the tip of the pole vertical height to the wall height. Also you will need the distance from the pole base to the wall for your x component.
Your Cartesian window to plot this equation will be fixed at that geometry.
D
Deleted member 4993
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I think each "curve of intersection" can be expressed as a catenary -
y = A*cosh(x/b) + C
The surface of each "face" will take different shape - depending on the wind load and the tensions.
y = A*cosh(x/b) + C
The surface of each "face" will take different shape - depending on the wind load and the tensions.