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Does this even meet the criteria for "a shape"? I'd have thought you need to be able to travel from any point within the shape to any other point, without crossing a line.
The part showing the angle is not part of it. They should've made it a dotted line or something.
Though, two of the 90° angles are.actually 270.
Thank you that was helpful.
The classic cartoon star shape isn't a shape with that rule. Same wth a crescent
I don't know what a french pastry has to do with this.
Are you sure about that?
Huh? Of course it is. A star is, so long as you don’t draw it out of two interlocking triangles, or construct it from 5 straight lines, and leave the internal parts of those lines intact. A crescent just…is. Unless you’re trying to claim the stars that sometimes appear with a crescent (e.g. on some Islamic country’s flags) are a part of the crescent itself.
Wait, you don't mean the line has to be straight? If that's what you mean, I'm fairly sure the internal lines in the post are only there as construction. The section of the triangle that's inside the smaller circle is just there to show dimensions, so it's drawn (slightly) thinner than the external lines
That sounds like the definition for convex shape, not the general definition for a shape
it doesn't have to be a straight line between points eh
Then this shape does meet the definition
yes i concur
You’re the second person to have made that suggestion to me, but no.
If you're talking about straight lines, then yes, that's how you define a convex shape. If any uninterrupted path can be taken, then the OP shape does satisfy the condition.
Edit: just read the other comments and I see the problem was that you thought the internal angle shown for reference on how the shape was built is part of the shape. It's not, just the thicker lines define the shape shown. The little crossmarks that show equal sides are also not part of the shape.
Depends how you define a shape. I don't think it's a polygon because it doesn't have straight lines. Technically a circle also isn't a polygon by the same rules, but circles have their own special little clubhouse. Sure is a shape though. I think this... thing is also a shape. Just not a useful one.
Idk seems very useful to me, like if I need a paperweight or doorstop
As it was presented in the OP, I don’t think it is a shape. If I get two squares and stick them next to each other so one side of each is touching, have I suddenly got one rectangle? Or do I still have two squares with a border between them?
Someone else posted an amended version with the internal lines removed. The equivalent of taking those two squares and removing the border between them, so you would have just one rectangle.
Concave shape vs convex shape
Uhh, no. A crescent is a classic concave shape, but you can travel from any point to any other in a crescent without crossing a line, because it’s a single enclosed shape.
A crescent isn't a convex shape though, and ironically you left out the word 'straight' in your rule about convex.
No irony, I didn't say straight because I didn't mean straight. I meant exactly what I said: you can get from one point to another without crossing a line. Because if you have to cross a line, you've either moved into a different shape (in the case of two adjoining shapes) or moves into empty space.
That's path connectedness. Convex shapes are ones in which any two points can be joined by a straight line internal to the shape.
I couldn't find any definition of geometric shape that uses that criterion, including Wikipedia which also has a 5-pointed star shown with 5 line segments labelled as a shape: https://en.m.wikipedia.org/wiki/Shape.
The meme is wrong because squares are polygons by definition, which by definition are made of line segments, but this thing has curved sections.