Theory:

In the earlier classes, we have learnt the intersection of two lines. Now, let us analyse what happens if a curve and a line are on a plane.
 
Let us discuss some situations when a circle and a line intersect.
 
Situation 1: The line \(AB\) does not touch the circle.
 
Sit 1.png
 
Here, there is no common point between the straight line \(AB\) and the circle.
 
Therefore, the number of points of intersection is zero.
 
Situation 2: The line \(AB\) touches the circle at one point.
 
Sit 2.png
 
Here, there is one common point \(P\) between the straight line \(AB\) and the circle.
 
The line \(AB\) is called the tangent to the circle at \(P\).
 
Therefore, the number of points of intersection is one.
 
Situation 3: The line \(AB\) touches the circle at two points.
 
Sit 3.png
 
Here, there two common points \(P\) and \(Q\) between the straight line \(AB\) and the circle.
 
The line \(AB\) is called the secant of the circle.
 
Therefore, the number of points of intersection is two.
 
Important!
The line segment inscribed in a circle is called the chord of the circle.
 
Chord.png
 
The chord is a sub-section of a secant.