Sometimes. Any face can be defined as a base of a prism; but pyramids may have one face that is a base and not a triangle.
Any shape you like.
A pyramid.
3D is a term used to describe space figures. They occupy space and have volume. A 3D shape is also called solid figure , solid shape , space figure and 3D figure.
only a 3D figure has a face so no
It means the base in a 3D figure. For example, if it was a pyramid. the bottom part would be the base and you get the area of that base
You find the base of a figure depending on if it's 2D or 3D 2D- Get a measuring device and find the length of the base. 3D- Easiest way is to split it into parts. For example, you have a pentagon-shaped base, i would split it into 5 and find the base for 1 part and multiply it by 5.
polyhedron
sqaure base pyramid
A triangular base pyramid would fit the description.
Since a face of a 3d figure is the same as a side, you have two faces sharing a face! The result is lots of coincident faces!
Sometimes because a sphere which is a 3d figure has a diameter
A triangular pyramid. It has triangles on its 3 sides and a triangle on the bottom for a base.