Question

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area. class 9​

Answer 1

Step-by-step explanation:

Given:-

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm.

To find:-

Find its curved surface area of the cone ?

Solution:-

Diameter of the base of the cone = 10.5 cm

We know that

Radius = Diameter/2

Radius of the base of the cone = 10.5/2 = 5.25 cm

Slant height of the cone = 10 cm

We know that

The radius is 'r' units and slant height is 'l' units of a cone then the Curved Surface Area of the cone is CSA = πrl sq.units

=>CSA = (22/7)×(5.25)×10 sq.cm

=>CSA = (22×5.25×10)/7 Sq.cm

=>CSA = 1155/7 sq.cm

=>CSA = 165 sq.cm

Answer:-

Curved Surface Area of the given Cone =

165 sq.cm

Used formulae:-

• The radius is 'r' units and slant height is 'l' units of a cone then the Curved Surface Area of the cone is CSA = πrl sq.units

• π=22/7