what is point symmetry?
336862
Point symmetry exists when a figure is built around a single point called the center of the figure.  For every point in the figure, there is another point found directly opposite it on the other side of the center.
7662
A point does not have a direction. So I guess the answer is yes.
247013
this is not so easy to answer without doing some work: usually, when you speak of tessellation, it's more likely to deal with symmetries.\n\nHere is a good site which has a couple of interesting articles and softwares on tessellations:\n\nhttp://www.scienceu.com \n(click on the "Geometry center" icon)\n\nAnyway, I'll think better about it: it's a good question.
471467
Yes. A square has an order of rotational symmetry of 4. \nThis means that if you were to rotate a square 360 degrees (1 complete revolution) about the intersection of its diagonals, you will get 4 as the number of times it takes on the initial form in terms of position and alignment.
492854
ok, lets make this simple.\n\nIf a shape can be folded over itself and cover itself exactly, the article is said to be symmetrical and the "fold line" is said to be an axis of symmetry.\n\nA square is a symmetrical shape with 4 axis of symmetry, the two diagnals and one line drawn across it half way up, one line drawn down through it, half way across it.\n\nA circle has an infinate nubber of axis of symmetry, each one being a diameter.\n\nOne way to look at this axis is to think of it as a mirror placed on a plain geometrical shape, the reflection is the other half of the shape.
564625
Center is a point. Therefore we can think any direction from a point.\n\nAny thing that is opposite to it in a given direction, is opposite to the center.
1136639
In the Standard Model, quarks, electrons and the like are considered to be pointlike. This gives problems at short distances where for instance the electromagnetic force between two of them becomes infinite.\n\nThe basic idea of stringtheory is that the fundamental constituents of matter are strings of a length of order of 10^35 m which vibrate at specific frequencies. However, the simplest string theories give more problems then they solve and consistent theories requires more then four dimensions. \n\nMembranes take the idea even further.  The particles are represented by vibrating surfaces and higher dimensional objects.
491376
I would call it anterior to posterior/dorsal to ventral bilateral symmmetry - that is, if you drew a line through the animal from the front to back connecting its top and bottom, the resulting halves would be symmetrical.  However, I don't know if there are really specific types of bilateral symmetry - usually things are defined as asymmetrical, bilaterally symmetrical, or radially symmmetrical.
490916
In geometrical optics with a pointlike sun the airplane would cast a shodow on the surface.\n\nBut: 1) The sun isn't pointlike but appears as a disc in the sky, so if light from diffent edges of the disc would cross under the plane ther would be no sharp shadow anymore, from a viewpoint on the surface the plane wouldn't cover the sun as whole\n\n2) Light is a wave, so geometic optics is not the whole story, there is refraction that bends the light into the shadow region. That's what you call "refill the void".
834801
the geometrical center and center of gravity match only for object that have symmetrical shape (around an axe or point: like a cylinder or sphere) and a constant density
96228
If you rotate a point A=(a,b) 90 deg C.C.W about the origin, new coordination will be (-b,a). \n\nIf you rotate the point about some other point like (m,n) in a same manner, new coordination will be (n+m-b,a-m+n)\n\nProof:\nMove the origin to (m,n), then new coordination will be:\n(a-m,b-n) \nThen rotate it:\n(n-b,a-m)\nthen move the origin back:\n(n+m-b,a-m+n)
675710
radial symmetry\n\n  • noun chiefly Biology symmetry about a central axis, as in a starfish.
829392
just a piont of view, but normally to divide something symmetrically you have to do it at the widest piont along the centre line. where as assymetricaly is off the centre line at a narrower piont and therefore not a symmetry,this only applies to poloygons and symmetric shapes.  hope this helps
869679
All points on a vertical line have the same x-coordinate.  So, their equations are always x = that number.  Here you know that one point has an x-coordinate of -1, so all the others will too.  Therefore its equation is x = -1.
46678
The most popular atomic geometries are Linear, Trigonal Planar, Octahedral and Tetrahedra.\n\nI've added a link to a visualization program, though I couldn't get the plug-in to work.
701749
equi meaning all equal...\nat all point in the surface, potential is the same...\ni may be wrong in this part : \nbut a certain potential corresponds to a certain vector...\nwith equal potential, vector orientation is the same... when they intersect, your surface is not equipotential anymore...
443662
A three dimensional coordinate (point in space) reads (x,y,z).\nSo, (1,2,-2) = (x,y,z) clearly implies that x=1, y=2, and \nz= -2, as you required.