PA and PB are two tangents drawn from an external point P to a circle with Centre O and radius 4 cm if PA perpendicular PB find th

PA and PB are two tangents drawn from an external point P to a circle with Centre O and radius 4 cm if PA perpendicular PB find the length of Each tangent​

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Allison

2 thoughts on “PA and PB are two tangents drawn from an external point P to a circle with Centre O and radius 4 cm if PA perpendicular PB find th”

  1. Diagram:-

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    Given:

    • OA=OB=4cm (Radius)
    • ∠APB=90°
    • AP & PB=Tangents

    To find:

    • Length of Tangents

    Solution:

    ⇒ ∠PAO=∠PBO=90°(angle made by Tangent with radius)

    Now,

    ⇒ ∠APB+∠PBO+∠PAO+∠AOB=360°(Sum of all ∠ of quadrilateral)

    ⇒ 90°+90°+90°+∠AOB=360°

    ⇒ 270°+∠AOB=360°

    ⇒ ∠AOB=360°-270°

    ⇒ ∠AOB=90°

    Now join AB in diagram

    ~Applying Pythagoras theorem in ∆AOB

    ⇒ AO²+OB²=AB²

    ⇒ (4cm)²+(4cm)²=AB²

    ⇒ 16cm²+16cm²=AB²

    ⇒ 32cm²=AB

    ⇒ √32cm²=AB

    ⇒ 4√2cm=AB

    Now assume length of each tangent be x

    Since, PAB is a right angled ∆, we can apply Pythagoras theorem in it.

    ~Applying Pythagoras theorem in ∆PAB

    ⇒ PA²+PB²=(4√2cm)²

    ⇒ x²+x²=32cm²

    ⇒ 2x²=32cm²

    ⇒ x²=32cm²/2

    ⇒ x²=16cm²

    ⇒ x=√16cm²

    ⇒ x=4cm

    So the required length of tangent is 4cm.

    Reply
  2. Answer:

    CA is perpendicular to AP and CB is perpendicular to BP

    Again AC = BC = 4 (radius of the circle)

    Also AP = PB = (Tangents from point P)

    So, BPAC is a square.

    => AP = PB = BC = CA = 4 cm

    So, length of tangents are 4 cm each

    I hope this helps!

    Reply

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