# What is Shapes: Definition and 164 Discussions

A shape or figure is the form of an object or its external boundary, outline, or external surface, as opposed to other properties such as color, texture, or material type.
A plane shape, two-dimensional shape, or 2D shape (plane figure, two-dimensional figure, or 2D figure) is constrained to lie on a plane, in contrast to solid figures.

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1. ### Valid Shapes of DNA: Is A Reasonable?

I'm designing a ... let's call it a sculpture. It represents DNA. I just realized there are (at least) two ways helices can spiral together: A has two helices that are concentric but with different radii. They are also "in phase". B has two identical helices that are "out-of-phase" by 180...
2. ### Load and Stress; 3 angles with different shapes corners

Summary: Each angle has a different type of corner, rectangular, circular, and triangular. Which one is the strongest? All three angles are mounted in the ground and made of the same material. The same force ‘w’ towards the ground is acting on all angles, which one is the strongest? Please...
3. ### Medical How does human eye decode different geometric shapes such as circle?

Hi, How does a human eye classify any shape as a circle, square, triangle etc.? Let's focus on a circular shape. Suppose we have a circle drawn in white on a black surface. The light falls on the retinal cells. I think the light falling on the retina will constitute a circular shape as well...
4. ### The 8 Mode Shapes of a plane finite element

I recall, about 30 years ago, seeing the eight mode shapes (and eigenvalues) of a single plane stress (or strain) finite element. Also, years ago, I wrote a FORTRAN code to obtain them (using IMSL libraries) I know there are eight (because the plane quad element had 8 degrees of freedom) I...
5. ### I Encircled energy for different aperture shapes (circle, triangle, square)

Hi all, I have a system whereby, there are different aperture shapes which are: circle, triangle, square e.t.c. this apertures are all 300um in diameter. I will like to know if the encircled energy calculated for the different apertures after diffraction will be different due to different...
6. ### Why constant pressure over different shapes produces the same force?

Left and right piston produce same vertical force.On both piston, side force is zero,how this is possible if left piston don't has simetrical shape? Why shape of object is irrelevant when fluid has constant/same pressure around object? How can I prove with integration of pressure over left...
7. ### What is the distance R between centers of mass in a barbell-shaped object?

Normalizing respect m, M, R and k then the normalized force for the case of the bar bell body aligned with the direction of R become Fn = 1/(1+x)^2 + (1-x)^2 is a vectorial sum but in this case the vectors are aligned We can assume x<<1 but is not really material to the problem For...
8. ### I Can Complex Shapes Be Rotated in 4D?

I have seen videos of a 4D rotation of a cube or tesseract. Was wondering if complex shapes can be processed into 4D rotation versions of themselves?
9. ### Diffraction of light around slits forming shapes

Just wanted to confirm whether or not the images formed by light shining through hexagonal slits are hexagons rotated by 90 degrees. In the solutions, a hexagon was not rotated 90 degrees.

11. ### Aerodynamics - Question about wingtip shapes

Short of picking up an aerospace engineering book and learning a lot of complex math, I figured I'd ask here. Looking at the wing tips of planes like the Spitfire, P-63 Air Cobra, P-47 Thunderbolt, A6M Zero, etc... you'll notice the wing tips are rounded. Looking at the wing tips of the P-51...
12. ### Water stream projection distance calculation for different nozzle shapes

Hello, I have built a device and i want to test different types of nozzles. Problem is; the size of the nozzles i need are hard to find in company stock. So i need to make sure before i make any order. I have no background or degree any related area so it is hard to understand the equations...
13. ### MHB Do Pi and Geometric Shapes Coexist?

(1) Is there a pi in ellipse entity?Why not or yes? (2) Is there a pi in polygons entities (e.g square)? not or yes? (3) If there is pi in some geometries and other not - What is the reason to that? (4) How cloud I know that are no hidden formula of pi in a square figure that the expression in...
14. ### B Exploring String Theory: Open and Closed Strings

are open strings like world lines? and closed strings like loops?
15. ### List of drag coefficient for basic shapes has no angles

When I type "drag coefficient" in Google, and view some of the images, the standard list of geometrical shapes come into view, such as this one: https://upload.wikimedia.org/wikipedia/commons/thumb/3/37/14ilf1l.svg/220px-14ilf1l.svg.png If we take the cone for example, there is a drag...
16. ### ANSYS Workbench -- What does "extra deformation shapes" mean?

Hello! I read from ansys element reference that for solid 65 the key option (1) is used to include or suppress extra deformation shapes. I would like to ask what extra deformation shape mean.
17. ### B Properties and Behaviors of an Object

Hi everyone. I want to build beautiful objects in a computer - object means something which has shape and behavior. I feel comfortable in writing down behavior of an object but I am struggling with writing shape of an object. A Table: Wave-forms: Is it possible to build any shape and any...
18. ### Chinese remainder theorem (CRT) question, flat shapes

Homework Statement By hand, find the 4 square roots of 340 mod 437. (437 = 23 * 19). Homework Equations Chinese remainder theorem (CRT) The Attempt at a Solution So this is the wrong way I did it was first I solved ##x^2 \equiv 340 (\operatorname{mod} 19)## and ##x^2 \equiv 340...
19. ### How to calculate the moment of inertia for complex 3D shapes

<<<moved from another sub forum, no template>>Hi, I need to calculate the moment of inertia for the component in the attached image so that i can calculate the angular momentum. Is it possible? Overall i am trying to calculate the forces on this lug as it passes around a 3" radius at 2M a...
20. ### I "Banana clock shapes" puzzle on social media

I looked for an answer to this question other places but found none. There is a puzzle going around that people are getting the answer wrong to. No surprise there. According to the proofs I found for it on the internet, my assumptions were true and I did arrive at the right answer (38...
21. ### I Understanding Black Hole Shapes & Forms

Sorry, I'm not sure what is the more appropriate word to use: shape or form. Let's to the question: How do we know what the shape of a given black hole is? I mean, how do we know whether it is spherical or whatever other form it has? Specifically, where do we look on the equations to get this...
22. ### Steel Vibration Synthesizer: Crafting Musical Shapes

Homework Statement Hello there, I thought a fully analog , cutting vibrational shapes on steel plate and hit to each shape by fingers and produce whichever sine , square , triangle vibration you want and filter of those collections of vibrations by another steel cut shape and make a synthesizer...
23. ### B Rectangular Prism out of different shapes?

Is it possible to create a rectangular prism while using only one prism and without repeating any two shapes?
24. ### Automotive Mode shapes of half-rhombus mechanism

I want to determine the natural frequencies and the mode shapes of the given mechanism ( it consists of 2 inclined beams connected together by a compliant link, the bottom end is fixed and the upper end is a roller support). I have done Finite element modeling but I need to get some analytical...
25. ### MHB Permutation question concerning cycle shapes

Consider the subset of $S_4$ defined by $$K_4=\{(1)(2)(3)(4),(12)(34),(13)(24),(14)(23)\}$$ Show that for all $f \in K_4$ and all $h \in S_4$, we have $h^{-1}fh \in K_4$ I showed all the possible cycle shapes of h and am trying to show that $h^{-1}fh$ must always have cycle shape $(2,2)$...
26. ### Investment casting of complex shapes

Hi guys, I am learning about investment casting at the moment and have a question I would love someone to answer. In investment casting a wax pattern needs to be created. How would that be made for a complex shape like an impeller? I've heard that lots of impellers are created using...
27. ### MHB Can anyone tell me the real names of these 3D shapes?

I know cylinder, cone and cube, but can't think of the names for the last two. I know this is a very basic question that I should know...but I am blanking.
28. ### B Modal Analysis & Mode Shapes: Real-World Applications

What is modal analysis and what are mode shapes. Plz explain along with a real life problem for better understanding
29. ### B Shapes and gravitational radiation

IIRC , a perfect sphere will not be detectable with a gravitational detector, but an ovoid shaped body will, why is this so? or am i wrong.
30. ### MHB Finding the Area of a shaded region (two shapes)

Hello, I've done something similar to this before but this question is really different because it contains two shapes. Now I'm really confused and I really appreciate the help~! -Cheers
31. ### Generalizing collision normal between two arbitrary shapes

I am working on a physics engine, and I have a question about the collision normal. There are a lot of different ways people say to calculate this, perpendicular to the collision angle, perpendicular to the edge of body 'B', etc. I was wondering if it would be okay to assume the collision...
32. ### Exploring the Benefits of Ionocrafts and their Equilateral Triangle Shapes

Hmmm maybe this goes here, maybe it doesn't. https://en.wikipedia.org/wiki/Ionocraft Here is a picture that depicts basically what I'm talking about. From what I understand, Ionocrafts work on N3L, and shoot ions down, pushing the craft up. This makes me think that the more charges you have...
33. ### B Detecting Unusual Stellar Shapes: Looking for Perturbed Planets

How can we be sure that when looking for planets there sun is not a perfect sphere and just looks like it is being perturbed by a gravitating body?
34. ### Charged particles through various B field shapes quesion

Hi, first of all I wan to ask a few simple questions , when we move a piece of wire perpendicular to a uniform magnetic field like between the faces of two magnets facing N-S we get a current either one or the other way in the wire , yet when we would shoot an electron beam the same path as the...
35. ### Finding the Missing Side Length of a Composite Shape

Homework Statement Homework Equations A = l x w A = hbb / 2 The Attempt at a Solution To find the area of a rectangle you would use the formula "A = L x W". In this case A = 14 x 8 which is eual to 112, Now all i need is the area of the triangle and then i add them together and that will be...
36. ### How Do You Calculate the Total Area of Rectangles and Triangles Combined?

Homework Statement 2. Homework Equations A = l x w A = b x w / 2 The Attempt at a Solution I calculated all the areas for the triangles and rectangles. So for the first rectangle (the long one) I did (L)(w) = A. Basically 8 x 2 = 16m2 (this is the same area for the other long rectangle)...
37. ### Defining rho in spherical coordinates for strange shapes?

Homework Statement The problem asks for a single triple integral (the integrand may be a sum but there must be a single definition for the bounds of the integral) representing the volume (in the first octant) of the shell defined by a sphere of radius 2 centered around the origin and a sphere...
38. ### Centrifugal Impeller and blade shapes

According to my lecture notes, for centrifugal impellers Backward curved blades have a outlet blade angle of less than 90, radial blades have curved blades have a outlet blade angle of 90, Forward curved blades have a outlet blade angle of more than 90. As such i have 2 questions 1) does the...
39. ### Are Electron Orbitals Always Spherical in Shape?

The probability distribution of the position of the electron of a hydrogen atom is related to the following polar plots Suppose the electron is excited from the ##1s## orbital to the ##2p_x## orbital. Does it make sense to talk about the ##2p_x## orbital having a dumbbell shape pointing in...
40. ### Why do spheres roll easier than cubes?

I am aware that this could be the wrong section for this, but I wish to ask this here if you all don't mind. You all know how a sphere rolls along the ground easier than a cube, right? Well, how are the physics of motion involved in why a sphere rolls easier than a cube, or an irregular object?
41. ### What Is the Shape of This Lamp?

can you tell me what shape this lamp is? like hexagon... many thanks for your help!
42. ### 3D object represent with primitive shapes

Hi, Given a 3D object in R3 space can we represent it using three basic primitive shapes like Sphere, Cone and Cylinder? Would this claim be valid?
43. ### MHB Geometric Shapes in Everyday Life

What are the geometric shapes that you can find in daily life?
44. ### High power bushing (HV power line insulator shapes)

Hello, I would like to understand why "bushings" that are used as insulation for high power electric cables in transformers, and which are often made out of porcelain or glass, I would like to understand why they have this form of "skirts" ? Why aren't they just as a simple cylinder?
45. ### Shapes of black holes (energy talk)

ok, hear me out on a lymph, because I'm going to either be talking crap or something that sounds crazy either way... my question is: why does the phenomena of a black hole look so perfectly circular/spherical? now here's my reasoning spheres are the shape that takes the least energy to be...
46. ### Parametric equations of various shapes

How we can know the parametric equation for any curve? Is there some trick? Like for parabola ## y^2 =4a x ## It has general coordinates## (at^2 , 2at) ## It will satisfy the equation but how in first place we know it? Also we can have ##(a/t^2, -2a/t) ##, how?
47. ### Exploring the Ripple Effect: The Mystery of 3D Shapes

Why does it look like a ripple on a pond instead of a three dimensional object?
48. ### What shapes do d orbital represent?

In d orbital there are 5 degenerates. How ## d_z^2 ## represents something like a donut shape. Shouldn't it be a parabola with respect to z axis, like when plotting graph of ## x^2 ##. Also have confusion about shapes of other 4 degenerates. For s it is spherical and simple. For p there are 3...
49. ### Mode Shapes of Machine Tool w/ Mass m & Moment of Inertia J0

Homework Statement A machine tool with mass ##m = 1000## kg and mass moment of inertia of ##J_0 = 300## kg-m##^2## where ##k_1 = 3000## N/mm and ##k_2 = 2000## N/mm which are located at ##\ell_1 = 0.5## m and ##\ell_2 = 0.8## m. Find the natural frequencies and mode shapes of the machine tool...
50. ### MHB Finding Side Lengths of Tangram Shapes

Hello, I'm trying to find the lengths of the sides of all of the shapes in the below tangram. This is what is given: • 2 large, and congruent, isosceles right triangles • 1 medium isosceles right triangle • 2 small, and congruent, isosceles right triangles • 1 square • 1 parallelogram The...