From a point T outside a circle of centre O, tangents TP and TQ are drawn to the circle. Prove that OT is the right bisector of line segment PQ.
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Answered by
88
we know : tangent at any point of a circle is perpendicular to radius.
so <opt=< oqt= 90degree
In triangle opt and triangle oqt
OP=OQ ( radii of same circle)
<OPT=<OQT =90degree
OT=OT ( common)
so triangle OPT=OQT
so PT = PQ ( by c.p.ct)
so in quadrilateral OPTQ
OP= OQ; PT=QT and <OPT=<OQT
so it is a kite
nd v know in kite diagonals are perpendicular to each other and longer diagonal bisect smaller diagonal.
so <opt=< oqt= 90degree
In triangle opt and triangle oqt
OP=OQ ( radii of same circle)
<OPT=<OQT =90degree
OT=OT ( common)
so triangle OPT=OQT
so PT = PQ ( by c.p.ct)
so in quadrilateral OPTQ
OP= OQ; PT=QT and <OPT=<OQT
so it is a kite
nd v know in kite diagonals are perpendicular to each other and longer diagonal bisect smaller diagonal.
Answered by
107
Given : A circle with centre O. Tangents TP and TQ are drawn from a point T outside a circle.
To Prove : OT is the right bisector of line segment PQ.
Construction : Join OP & OQ
Proof : In ΔPTR and ΔQTR
In ΔOPT and ΔOQT
∠OPT = ∠OQT = 90°
OP = OQ (radius)
OT = OT (Common)
ΔOPT ≅ ΔOQT (By RHS congruence)
∠PTR = ∠QTR (cpct)
TP = TQ (Tangents are equal)
TR = TR (Common)
∠PTR = ∠QTR (OT bisects ∠PTQ)
ΔPTR ≅ ΔQTR (By SAS congruency)
PR = QR
∠PRT = ∠QRT
But ∠PRT+ ∠QRT = 180° (as PQ is line segment)
∠PRT = ∠QRT = 90°
Therefore TR or OT is the right bisector of line segment PQ
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