A right angled sector of radius r cm is rolled up into a cone in such a way that the two binding radii are joined together. Then the curved surface area of the cone is

A right angled sector of radius r cm is rolled up into a cone in such

1.	A right angled sector of radius r cm is rolled up into a cone in such a way that the two binding radii are joined together. Then the curved surface area of the cone is
A.	r cm
B.
C.	4 r cm
D.	<table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> r </center></td><td rowspan="2">cm </td></tr><tr><td style="text-align: center;">4</td></tr></table>
E.	2 r cm
Answer» D. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> r </center></td><td rowspan="2">cm </td></tr><tr><td style="text-align: center;">4</td></tr></table>

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A right angled sector of radius r cm is rolled up into a cone in such a way that the two binding radii are joined together. Then the curved surface area of the cone is

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