A 3D shape with one base and three faces can only have triangular faces.
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.
A circle is not a 3D figure because it only has two dimensions. A sphere is a 3D "circle".
A 3D figure shows length, width and depth. While a 2D figure only shows length and width.
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.
A pyramid (3D)! Some examples: - triangular base pyramid - square base pyramid - rectangular base pyramid - cone
In 2D, the only figure would be some type of dodecagone. In 3D however, there are many possibilities. One of them is the decagonal bipyramid
A triangular base pyramid would fit the description.