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.
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.
I think I got your confusion? The shape in the post image has part of the “triangle” going into the circle, but those seem to be just projections to show the virtual angle between those lines, and are thinner than the rest.
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.
But not in a single straight line.
I think I got your confusion? The shape in the post image has part of the “triangle” going into the circle, but those seem to be just projections to show the virtual angle between those lines, and are thinner than the rest.