Two circles intersect at A and B. AC and AD are respectively the diameters of the circles. Prove that C, B and D are collinear. -Maths 9th

1 Answer

Answer :

Join CB, BD and AB, Since, AC is a diameter of the circle with centre O. ∴ ∠ABC = 90° [angle in semi circle] ---- (i) Also, AD is a diameter of the circle with center O . ∴ ∠ABD = 90° [angle in semi circle] ---- (ii) on adding Eqns,  (i) and  (ii) we get  ⇒ ∠ABC +  ∠ABD = 180°  So. CBD is a straight line. Hence C, B and D are collinear . Hence proved.

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