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A. O. P. B. 11. Tangents to Circles. (a) How to memorize the tangent properties?. If PA and PB are tangents from P to the circle. at points A and B respectively:. ∠ AOP =∠ BOP. ∠ AOP =∠ BOP. tangent properties. ∠ APO =∠ BPO. ∠ APO =∠ BPO. PA = PB. PA = PB.
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A O P B 11. Tangents to Circles (a) How to memorize the tangent properties? If PAand PBare tangents from P to the circle at points A and B respectively: ∠AOP=∠BOP ∠AOP=∠BOP tangent properties ∠APO=∠BPO ∠APO=∠BPO PA=PB PA=PB Tangent propertiesEasy Memory Tips: △APO △BPO(AAS) S A A i.e. the corresponding angles in the two triangles are equal: ∠AOP=∠BOP ∠APO=∠BPO and the corresponding sides of the two triangles are equal: PA=PB
B C Q P A 11. Tangents to Circles (b) How to memorize the angle in the alternate segment? The angle between the The opposite angle = from the chord tangent and the chord Angle in Alternate SegmentEasy Memory Tips: Use a torch to light up chord AC from B, then use another torch to light up chord AC from A. We can find an overlapping region which the two torches lighted up. The overlapping region is exactly thecorresponding positions of ‘∠ in alt. segment’.