.
Labelthe figureas shown.In , and.Therefore,tangentis perpendicularto the radius.tangentis perpendicularto the radius.Therefore, both equalsameangle.~ by the similaritypostulate.Therefore,InternallyTangentCircles
Hereis an exampleinvolvinginternallytangentcircles.
Example 5
Two diametersof a circleof radius15 inchesare drawnto makea centralangleof. A smallercircle
is placedinsidethe biggercircleso that it is tangentto the biggercircleand to both diameters.Whatis the