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From Karnataka Open Educational Resources
720 bytes added ,  06:39, 21 May 2019
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====== [[Congruent chords are equidistant from the centre of a circle|Congruent chords are equidistant from the center of a circle]] ======
 
====== [[Congruent chords are equidistant from the centre of a circle|Congruent chords are equidistant from the center of a circle]] ======
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In the same circle or in circles of equal radius:
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• Equal chords are equidistant from the centre.
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• Conversely, chords that are equidistant from the centre are equal.
    
====== [[Angles in a circle subtended by a chord]] ======
 
====== [[Angles in a circle subtended by a chord]] ======
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==== Concept #5: Cyclic Quadrilateral ====
 
==== Concept #5: Cyclic Quadrilateral ====
A quadrilateral ABCD is called cyclic if all four vertices of it lie on a circle.In a cyclic quadrilateral the sum of opposite interior angles is 180 degrees.If the sum of a pair of opposite angles of a quadrilateral is 180, the quadrilateral is cyclic.In a cyclic quadrilateral the exterior angle is equal to interior opposite angle.
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In Euclidean geometry, a '''cyclic quadrilateral''' or inscribed '''quadrilateral''' is a '''quadrilateral''' whose vertices all lie on a single circle. This circle is called the circumcircle or circumscribed circle, and the vertices are said to be concyclic.
    
=====Activities=====
 
=====Activities=====
    
======  [[Cyclic quadrilateral]] ======
 
======  [[Cyclic quadrilateral]] ======
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A quadrilateral ABCD is called cyclic if all four vertices of it lie on a circle.In a cyclic quadrilateral the sum of opposite interior angles is 180 degrees.If the sum of a pair of opposite angles of a quadrilateral is 180, the quadrilateral is cyclic.In a cyclic quadrilateral the exterior angle is equal to interior opposite angle.
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=====[[Properties of cyclic quadrilateral]] ======
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=====[[Properties of cyclic quadrilateral]]=====
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Relation between the angles of a cyclic quadrilateral are explored with this hand on activity.
    
==== Concept #6 Constructions in circles ====
 
==== Concept #6 Constructions in circles ====
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======  [[Construction of direct common tangent]] ======
 
======  [[Construction of direct common tangent]] ======
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The direct common tangents to two circles meet on the line of centres and divide it externally in the ratio of the radii. 
    
====== [[Construction of transverse common tangent]] ======
 
====== [[Construction of transverse common tangent]] ======
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The transverse common tangents also meet on the line of centres and divide it internally in the ratio of the radii.
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====== [[Construction of cyclic quadrilateral]] ======
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====== [[Class10 circles tangents problems|Solved problems/ key questions (earlier was hints for problems).]] ======
 
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=====[[Class10 circles tangents problems|Solved problems/ key questions (earlier was hints for problems).]]=====
   
===Projects (can include math lab/ science lab/ language lab) ===
 
===Projects (can include math lab/ science lab/ language lab) ===
 
#Collect different types of circular objects
 
#Collect different types of circular objects