How about a hemisphere ?
A 3D shape with one base and three faces can only have triangular faces.
CONE
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 pyramid.
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.
To find the base of a figure, you first need to identify the shape of the figure. The base of a figure is typically the bottom or lower side that forms the foundation or support for the rest of the shape. For example, in a triangle, the base is usually the side on which the triangle stands. In a rectangular prism, the base is one of the two parallel and congruent rectangular faces.
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
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
polyhedron
A triangular base pyramid would fit the description.