Q: Is shape the form of an object or its external boundary? ¶
A: Yes, and outline, or external surface, as opposed to other properties such as color, texture, or material composition.
Q: Are shapes approximately the same? ¶
Q: Are shapes called geometrically similar? ¶
A: Yes, and whether or not they have the same size.
Q: Is shape an equivalence relation? ¶
A: Yes, and accordingly a precise mathematical definition of the notion of shape can be given as being an equivalence class of subsets of a Euclidean space having the same shape.
Q: Is shape an invariant of affine geometry? ¶
Q: Are shapes points? ¶
A: Yes, and lines, planes, and conic sections such as ellipses, circles, and parabolas.
Q: Are shapes often deformable, e.g? ¶
A: Yes, a person in different postures, a tree bending in the wind or a hand with different finger positions.
Q: Are shapes polyhedra, which are shapes with flat faces? ¶
A: Yes, ellipsoids, which are egg-shaped or sphere-shaped objects; cylinders; and cones.
Q: Is shape determined by only the outer boundary of an object? ¶