AnglesOutsidea Circle
TheoremThe measureof an angleformedby two secantsdrawnfrom a pointoutsidethe circleis equalto
half the differenceof the measuresof the interceptedarcs.
In otherwords:This theoremalso appliesfor an angleformedby two tangentsto the circledrawnfrom a pointoutsidethe
circleand for an angleformedby a tangentand a secantdrawnfrom a pointoutsidethe circle.
Proof