ray
It has two endpoints. A ray has one endpoint.
diameter
A ray = A half-line
a ray
A line segment is a portion of a line. It has length. It has two endpoints. A ray has only one endpoint. It has infinite length in one direction.
I am going to say a line segment. No segments is a line, and one endpoint is a ray.
Only one point. A dimensionless figure.
A cone
parallelogram
on any ray,there is exactly one point at a given distance from the endpoint of the ray
if you are talking about a geometric figure its the octagon
A rectangle.
a cone
A rectangular pyramid.
One possible answer is: a point.
None. Degrees are a measurement of angle.
A geometric figure with a polygonal base and triangular sides is called a pyramid.