Not necessarily. If it is a semicircle - a circle bounded by an arc and the diameter of the original circle, it has two vertices - at the end of the diameter.
However, a half circle need not have a side that is a straight line. It can be like the yin-yang symbol (see link). The half circle here has no vertex.
The shape that has no vertices and is round is a circle. The circle is the only shape that does not have vertices.
Zero vertices
None but it's possible to construct shapes within a circle that have vertices.
Inscribed
Circle or sphere.
The shape that has no vertices and is round is a circle. The circle is the only shape that does not have vertices.
Zero vertices
A circle has no vertices and is round.
A circle has no vertices around it
A circle has no vertices and it has one face. It could also be argued that a circle is the limiting form of a regular polygon with an infinite number of vertices.
None but it's possible to construct shapes within a circle that have vertices.
A polygon whose vertices are on a circle and whose other points are inside the circle is called a "cyclic polygon." The circle is known as the circumcircle of the polygon, and all the vertices lie on its circumference. In addition to the vertices, the polygon may have additional points that are located within the circle, but those points do not change the cyclic nature of the polygon. Examples include triangles, quadrilaterals, and other polygons as long as their vertices are on the circle.
Inscribed
A circle
Circle or sphere.
Yes.
circle..