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 About the author Allison
Diagram:- [tex]\setlength{\unitlength}{1.1mm}\begin{picture}(50,55)\thicklines\qbezier(25.000,10.000)(33.284,10.000)(39.142,15.858)\qbezier(39.142,15.858)(45.000,21.716)(45.000,30.000)\qbezier(45.000,30.000)(45.000,38.284)(39.142,44.142)\qbezier(39.142,44.142)(33.284,50.000)(25.000,50.000)\qbezier(25.000,50.000)(16.716,50.000)(10.858,44.142)\qbezier(10.858,44.142)( 5.000,38.284)( 5.000,30.000)\qbezier( 5.000,30.000)( 5.000,21.716)(10.858,15.858)\qbezier(10.858,15.858)(16.716,10.000)(25.000,10.000)\put(25,30){\line(1,1){14}}\put(25,30){\line(1, – 1){14}}\put(39,15.8){\line(3,1){42}}\put(39,44.2){\line(3, – 1){42}}\put(39,16){\line(0,1){28}}\put(25,30){\circle*{1}}\put(81,30){\circle*{1}}\put(22,30){\sf O}\put(40,46){\sf A}\put(40,12){\sf B}\put(83,30){\sf P}\end{picture}[/tex] 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
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
Diagram:-
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Given:
To find:
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.
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!