Question

find the curved surface area of a frustum of a cone whose hight is 16cm and radii of its two ends as 8cm and 20cm respectively?

plxx gave meh right answer​

Answer 1

Answer:

Curved Surface area of a frustum of a cone =πl(r

1

+r

2

) where l is the slant height =

h

2

+(r

1

−r

2

)

2

h is the height.

r

1

and r

2

are the radii of the lower and upper ends of a frustum of a cone.

So, l=

16

2

+(20−8)

2

∴l=20cm

Hence, Curved surface area of this frustum of a cone =π×20×(20+8)=560πcm

2

Answer 2

Answer:

560πcm

Step-by-step explanation:

Curved Surface area of a frustum of a cone  =πl(r1+r2) where l is the slant height =h2+(r1−r2)2 h is the height. 

r1 and r2 are the radii of the lower and upper ends of a frustum of a cone.

So, l=162+(20−8)2

∴l=20cm

Hence, Curved surface area of this frustum of a cone  =π×20×(20+8)=560πcm2 

Hope you understand

Thank you