Q3 of 6 Page 116

O is the centre of the circle. Find the length of the radius, if the chord of length 24 cm is at a distance of 9 cm from the centre of the circle.



As we know that, the perpendicular from the centre of a circle to a chord bisects the chord.


So let P is the point, which bisects chord AB. So OP is perpendicular, it makes a right angle triangle ∆OPA.


Now we have OP = 9cm and AP as 12 cm


So by Pythagoras theorem,


AO2 = AP2 + PO2


AO2 = (12)2 + (9)2


AO2 = 144+81


AO2 = 225


AO = 15 cm


Length of radius is 15 cm.


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1

In a circle with centre P, chord AB is drawn of length 13 cm, seg PQ ⊥ chord AB, then find l(QB).


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Radius of a circle with centre O is 25 cm. Find the distance of a chord from the centre if the length of the chord is 48 cm.


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C is the centre of the circle whose radius is 10 cm. Find the distance of the chord from the centre if the length of the chord is 12 cm.

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The diameters PQ and RS of the circle with centre C are perpendicular to each other at C. State, why arc PS and arc SQ are congruent. Write the other arcs, which are congruent to arc PS