# How do you construct a common internal tangent to two circles?

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### 1 Answer

To construct a common internal tangent you need to remember what a common tangent is.

The line that is tangent to two coplanar circles is called common tangent.

There are two types of common tangent lines to two circles: common internal tangent and common external tangent.

How differs these two types of common tangents?

Draw a line joining the centers of the two circles then draw a common tangent.

**If the common tangent intersects the line joining the centers of the circles, then this tangent is called common internal tangent.**