It depends on the shape.
There are relatively straightforward formulae for a sphere, cylinder, cone, prism (including cuboid), pyramid. Less simple formulae for parallelepipeds, ellipsoids and perhaps complex ones for other simple shapes. And then you have seriously complex 3-d shapes (a lump of putty) for which there are virtually no direct formulae.
Volume
Well it depends on what kind of 3d shape it is. There is a formula to find the volume of each 3d shape. The main formula for volume is Bxh. (Big B multiplied by the height.) Bxh means the area of the base times the height.
The answer will depend on what "it" is.
The 3D space inside a shape is it's volume.
A 2D shape is flat and only has a surface area whereas a 3D shape is an object that has surface area and volume.
It's volume.
Volume
Well it depends on what kind of 3d shape it is. There is a formula to find the volume of each 3d shape. The main formula for volume is Bxh. (Big B multiplied by the height.) Bxh means the area of the base times the height.
The answer will depend on what "it" is.
Volume. The formula depends on the shape.
The 3D space inside a shape is it's volume.
A 2D shape is flat and only has a surface area whereas a 3D shape is an object that has surface area and volume.
Only if the shape is a cuboid.
It is a volume (3D) shape - "solid" has nothing to do with it.
It doesn't have any volume (3D) and it's not a line (1D). Thus, it is a 2D shape.
They are shapes that occupy a volume in space. They have a length, width (or breadth) and height.
That will depend on what they are but in general 3D shapes have surface area and volume whereas 2D shapes have only surface area.