Wed February 27, 2013 By:

mayank made a bird bath for his garden in the shape of a cylinder with a hemisperical depression at one end. the height of the cylinder is is 1.45m and its radius is 30 cm. find the TSA of the bird bath.(take pi as 22/7) pls refer to pg 244 of ncert txt bk example 4) sir can u plz explain why we don't include the base of the cylinder for the TSA?

Expert Reply
Thu February 28, 2013
Total Surface area of any object refers to what you can see on the outside. If you will see here, the top of the cylinder is open (since its a bird bath) and hence, its surface area need not be taken into account whereas on the other hand, at the other end we have a hemispherical depression and hence, we don't need to account for the area of base of the cylinder, but instead need to consider only the CSA of the hemisphere. 
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