In a right triangle ABC in which ∠B = 90°, a circle is drawn with AB as diameter intersecting
the hypotenuse AC and P. Prove that the tangent to the circle at P bisects BC
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QᏌᎬᏚᎢᏆᎾN
In a right triangle ABC in which ∠B = 90°, a circle is drawn with AB as diameter intersecting the hypotenuse AC and P. Prove that the tangent to the circle at P bisects BBC.
ᎪNᏚᏔᎬᎡ
ΔABC is a right angled triangle.
∠ABC = 90°.
A circle is drawn with AB as diameter intersecting AC in P, PQ is the tangent to the circle which intersects BC at Q.
Join BP.
PQ and BQ are tangents drawn from an external point Q.
∴ PQ = BQ -------------- (1) (Length of tangents drawn from an external point to the circle are equal)
⇒ ∠PBQ = ∠BPQ (In a triangle, angles opposit to equal sides are equal)
Given that, AB is the diameter of the circle.
∴ ∠APB = 90° (Angle in a semi-circle is a right angle)
∠APB + ∠BPC = 180° (Linear pair)
∴ ∠BPC = 180° – ∠APB = 180° – 90° = 90°
Consider ΔBPC,
∠BPC + ∠PBC + ∠PCB = 180° (Angle sum property of a triangle)
∴ ∠PBC + ∠PCB = 180° – ∠BPC = 180° – 90° = 90° ----------- (2)
∠BPC = 90°
∴ ∠BPQ + ∠CPQ = 90° ...(3)
From equations (2) and (3), we get
∠PBC + ∠PCB = ∠BPQ + ∠CPQ
⇒ ∠PCQ = ∠CPQ (Since, ∠BPQ = ∠PBQ)
Consider ΔPQC,
∠PCQ = ∠CPQ
∴ PQ = QC ----------- (4)
From equations (1) and (4), we get
BQ = QC
Therefore, tangent at P bisects the side BC.
Answer:
Yes this is the correct answer