The radius of the base of a right circular cone is 9 cm and its slant height is 49 cm. Find the curved surface area of the cone.

The radius of the base of a right circular cone is 9 cm and its slant height is 49 cm. Find the curved surface area of the cone.
एक समवृत्तीय शंकु के आधार की त्रिज्या 9 सेमी तथा उसकी तिर्यक ऊँचाई 49 सेमी है। शंकु का वक्र पृष्ठीय क्षेत्रफल ज्ञात कीजिए|

$1490 \text {cm}^ 2 $ $1265 \text {cm}^ 2 $ $1386 \text {cm}^ 2 $ $1262 \text {cm}^ 2 $