A wooden ar

Given:

• Cylinder with height(h) 10cm and diameter(2r) 7cm

• Hemispheres cut from the top and bottom

Total Surface Area = Curved Surface Area of Cylinder + Curved Surface Area of 2 hemi - spheres

= CSA of Cylinder + Total Surface Area of a Sphere

CSA of Cylinder = 2πrh where “r” is the radius of cylinder

“h” is the height of the cylinder

TSA of Sphere = 4πr² where “r” is the radius of the sphere

So,

Total Surface Area of the Article = 2πrh + 4πr²

= 2π(3.5)(10) + 4π(3.5)²

= 119π sq. cm

OR

Given:

• Height of Cone(h) = 3.5m

• Radius of the base(r) = 12m

The volume of the cone

where “r” is the radius, “h” is the height of the cone

= 168π cu. metres

And, Curved Surface Area of the Cone = πrl

where “l” is the slant height of the cone

Now,

(using the Pythagoras theorem)

= 12.5m

CSA of Cone = π(12)(12.5)

= 150π sq. metres

So, 168π m³ is the volume of the rice and, 150π m² of canvas cloth is required to cover the heap