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From Karnataka Open Educational Resources
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, 15:04, 12 August 2014
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== Problem-1==
== Problem-1==
#Tanjents AP and AQ are drawn to circle with centre O, from an external point A. Prove that ∠PAQ=2.∠OPQ <br>
#Tanjents AP and AQ are drawn to circle with centre O, from an external point A. Prove that ∠PAQ=2.∠OPQ <br>
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[[File:fig1.png|200px]]
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[[http://karnatakaeducation.org.in/KOER/en/index.php/Class10_circles_tangents_problems '''Solution''']]
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===Interpretation of the problem===
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#O is the centre of the circle and tangents AP and AQ are drawn from an external point A.
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#OP and OQ are the radii.
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#The students have to prove thne angle PAQ=twise the angle OPQ.
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===Concepts used.===
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#The radii of a circle are equal.
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#In any circle the radius drawn at the point of contact is perpendicular to the tangent.
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#The tangent drawn from an external point to a circle a] are equal b] subtend equal angle at the centre c] are equally inclined to the line joining the centre and extrnal point.
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#Properties of isoscles triangle.
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#Properties of quadrillateral ( sum of all angles) is 360 degrees
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#Sum of three angles of triangle is 180 degrees.
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===Algorithm===
== Ex 4.4.2==
== Ex 4.4.2==