Question

The curved surface area of a right circular cone of radius 3r and height 4r is

Answer 1

Answer:

radius = 3r

height = 4r

C.S.A of cone = πrl

= 3.14×3r×4r

= 3.14×12r²

= 37.68r²

Answer 2

Answer:

75.4 units

Step-by-step explanation:

the curved surface area= πr(r+√h2+r2)

=3π(3+√4×4+3×3)

=3π(3+√25)

=3×22/7×(3+5)

=506/7

=75.4 units

Therefore,the value of the given curved surface area is 75.4 units