Question

why right angle does not have curve extension??

Answer 1

Answer:

With an angle, the magnitude of the angle - measured in degrees, or radians, or grads - characterizes the angle completely. All angles of the same size are the same angle.

With an arbitrary curve, you'd have to describe the direction it goes at every point on the curve. It would take an infinite number of numbers to describe all its twists and turns.

If you confine yourself to a curve of a known form, then it might be meaningful to come up with a number that measures it. For instance, with a circular arc, it's pretty common to describe it in terms of the angle that it subtends at the center of the circle.

So I suppose the answer is, "not for an arbitrary curve, but possibly for a specific type of curve that you have in mind."

BE SMART ^_^