It is a polygonal pyramid.
a pyramid
A polygonal pyramid.
A polygon is a closed figure made of line segments. Therefore, a chevron is a polygon, specifically one that is concave.
Polygon
It is a polygonal pyramid.
a pyramid
Such a figure is a pyramid.
A geometric figure with a polygonal base and triangular sides is called a pyramid.
It could be a pyramid.
A polygonal pyramid.
It can be a triangular based pyramid
A polygon is a 2-dimensional figure bounded by three or more straight lines. Any one of its sides may be considered a base.
a polygonal prism or a polygond
A polygon is a many sided 2-dimensional figure, and thus could never be "solid" Alternatively, it could be "one face that is a polygon". In that case the solid could be like a pyramid that morphs into a cone or a part-sphere. The base would be the one polygon, the other face would not.
A circle is one example of a plane figure that is not a polygon. A V is also not a polygon.
Pyramid, base