If O is the centre of a circle of radius 5 cm. At a distance of 13 cm from O, a point P is taken. From this point, two tangents PQ and PR are drawn to the circle. Then , the area of quadrilateral PQOR is
Given : OQ = 5 cm and OP = 13 cm
To find : ar(PQOR) = ?
Solution : Â The radius intersects the tangent at the circumference of the circle at right angle.
=> $$\angle OQP=90^\circ$$
In $$\triangle$$ PQO
=> $$(PQ)^2=(OP)^2-(OQ)^2$$
=> $$(PQ)^2=(13)^2-(5)^2$$
=> $$(PQ)^2=169-25=144$$
=> $$PQ=\sqrt{144}=12$$ cm
Similarly, PR = 12 cm
$$\therefore$$ Area of quad(PQOR) = $$ar(\triangle POQ)+ar(\triangle POR)$$
= $$PQ \times OQ$$
= $$12 \times 5=60$$ $$cm^2$$
=> Ans - (A)
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