CK12 - Geometry

radiusof the smallercircle?

and are two tangentsto the smallercirclefrom a commonpointso by Theorem9-3, \overline{ON}

bisects

In we use

Draw from the pointsof tangencybetweenthe circlesperpendicularto.

In we use

We also have becausea tangentis perpendicularto the radius.

Therefore,

both equal

sameangle.

Therefore, by the similaritypostulate.

This givesus the ratio