common external tangent


Definition of Common External Tangent

  • A tangent that is common to two circles and does not intersect the segment joining the centers of the circles is called Common External Tangent.

More about Common External Tangent

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

Examples of Common External Tangent



 

  • In the above figure, line PQ is the common external tangent.

  • In the above figure, line AB is the common external tangent.

Solved Example on Common External Tangent

Identify the common external tangent from the given figure.

Choices:
A. AB
B. CD
C. EF
D. none of the above
Correct Answer: B
Step 1: A tangent that is common to two circles and does not intersect the segment joining the centers of the circles is called common external tangent.
Step 2: In the given figure, the line CD touches both the circles on the same side of the line is the external tangent to the circle.
Step 3: So, CD is the common external tangent line.

Related Terms for Common External Tangent

  • Circles
  • Common Internal Tangent
  • Segments
  • Tangents