The line drawn through the center of a circle to bisect a chord is perpendicular to the chord. Given:  A circle with center O, AB is chord of a circle and OC bisect chord at C. i,e. AC = CB. To prove: OC ⊥ AB Construction: join OA and OB.  Proof:  In △ OCA and △ OCB OA = OB (Radius […]

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If the angles subtended by chords of a circle at the center are equal, then the chords are equal. Given:  A circle with center O, AB and CD are chords of circle that subtend equal angles at center O. i,e. ∠AOB = ∠COD. To prove: chord AB = chord CD Proof: In △AOB and △ CODOA = OC (Radius of circle)∠AOB […]

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Congruent triangles Worksheet    Problems and Solutions Example : (1) In figure if AD = CD and AB =  CB. (i) Find the three pairs of equal parts in △ABD and △CBD. (ii) Is △ABD ≅ CBD ? Why or why not? (iii) Does BD bisect ∠ABC? give reason. Solution : (i) In △ABD and △CBD, three pairs of equal parts […]

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