A line.
a line
a ray
a road......?
resultant displacement
Most likely sinusoid.
A line.
it is called a ray
The shortest path between two points is called a geodesic. In flat (Euclidean) space it is simply a straight line.
Line
Straight means starting from one point and goes in same path and join at end point
A line.
If you mean a straight path, rather than a strait path, then it is a ray.
ray
A line is a straight path that extends infinitely or endlessly in opposite directions. A straight path that joins two points is called a line segment.
Ray
The immediate surroundings of any point on a curved path can be considered as part of a circle: the circle of curvature at that point. Then the tangent to the path at that point is a line that meets the path at only one point in that neighbourhood and which is perpendicular to the line joining the point to the centre of the circle or curvature. The concept can be extended to straight segments of the path by assuming that the centre of curvature is at an infinite distance. In that case, the path and its tangent are the same line.
A geodesical path