Internal Tangent of a Circle

Definition of Internal Tangent of a Circle

    A tangent that is common to two circles and intersects the segment joining the centers of the circles is called Common Internal Tangent.

More About Internal Tangent of a Circle

    A common tangent can either be a common external tangent or a common internal tangent.

Video Examples:Construction: Internal Tangents To Two Circles


Example of Internal Tangent of a Circle

       example of Internal Tangent of a Circle
    In figure, AB line is the common internal tangent of two circles.
       example of Internal Tangent of a Circle
    In figure, CD line is the common internal tangent of two circles.

Solved Example on Internal Tangent of a Circle

Ques: Identify the common internal tangent line from the given figure.
     example of Internal Tangent of a Circle

    Choices:
    A. AB line
    B. CD line
    C. EF line
    D. none of the above
    Correct Answer: A

Solution:

    Step 1: A tangent that is common to two circles and intersects the segment
    joining the centers of the circles is called Common Internal Tangent.
    Step 2: In figure, line AB is the common tangent as it intersects the segments joining the centers of two circles.
    Step 3: So, AB is the common internal tangent line.