a 3d object is a object that isn't flat. for instance, a square in 3d form would be a cube
Well, a 2D object has only length and width, but a 3D object has length, width, and depth.
a 2D object is is flat and on the other hand a 3D object is bulgy
Paper is a 3D object.
on a 3D object to find the surface is to look on all flat surfaces. yourwelcome
Um... What?
A sphere.
Maybe a circle and a triangle, and indeed a straight line are not 3D.
It is the volume of the object.
[object Object]
A Heptagon is a 3d object with 7 faces. An example of a heptagon is a hexagonal pyramid (that is a pyramid with a hexagon for the base).
Unless it is a 3-d net (an object made up only of lines in 3D space), all 3D objects will take up space.
a globe