Question

what is called a tangent​

Answer 1

Answer:

• geometry, the tangent line (or simply tangent) to a plane curve at a given point is the straight line that "just touches" the curve at that point.
• Leibniz defined it as the line through a pair of infinitely close points on the curve. ... The word "tangent" comes from the Latin tangere, "to touch".

Answer 2

Answer:

A tangent is a line which passes on a circle such that it is in contact with only one point on the circle's circumference.

Also, a tangent is perpendicular to the radius.