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# Curved Surface Area of a Cone is 308 Cm2 and Its Slant Height is 14 Cm. Find the Radius of the Base and Total Surface Area of the Cone. - CBSE Class 9 - Mathematics

ConceptSurface Area of a Right Circular Cone

#### Question

Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find the radius of the base and total surface area of the cone.

#### Solution

(1) Given that,

Slant height of cone= 14cm

Let radius of circular end of cone=r

Curved surface area of cone=pirh

308cm^2=(22/7xxrxx14)cm        [∵ CSA=308 cm^2]

⇒ r= 308/44cm=7cm

Thus, radius of circular end of cone= 7cm

(ii) Given that CSA= 308cm^2

WKT, total surface area of cone

=curved surface area of cone + area of base

= pirl+pir^2

=[308+22/7(7)^2]cm^2

= 308+154cm^2

= 462cm^2

Thus, the total SA of the cone is 462 cm^2

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Solution for Mathematics for Class 9 by R D Sharma (2018-19 Session) (2018 to Current)
Chapter 20: Surface Areas and Volume of A Right Circular Cone
Ex.20.10 | Q: 15 | Page no. 8
Solution Curved Surface Area of a Cone is 308 Cm2 and Its Slant Height is 14 Cm. Find the Radius of the Base and Total Surface Area of the Cone. Concept: Surface Area of a Right Circular Cone.
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