Q8 of 32 Page 119

The curved surface area of a cone is 2200 sq.cm and its slant height is 50 cm. Find the total surface area of cone.

(π = 22/7)

Given: Curved surface area of cone (CSA) = 2200 cm2

Slant height of cone (l) = 50 cm


For total surface area, we have the formula


TSA = πrl + πr2


⇒ TSA = CSA + πr2 [∵, Curved surface area (CSA) = πrl] …(i)


Where, r = radius of the base of the cone


We have CSA, we just need to find radius of the base of the cone (r).


So, we know


CSA = πrl


Substituting values in above equation,


⇒


⇒


⇒ r = 14


⇒ Radius of the base of the cone = 14 cm


Thus, substituting value of CSA and r in equation (i),



⇒ TSA = 2200 + 616


⇒ TSA = 2816


Thus, total surface area of cone is 2816 cm2.


More from this chapter

All 32 →
6

Surface area of a cone is 188.4 sq.cm and its slant height is 10cm. Find its perpendicular height (π = 3.14)

 7

Volume of a cone is 1212 cm3 and its height is 24cm. Find the surface area of the cone.

(π = 22/7)

 9

There are 25 persons in a tent which is conical in shape. Every person needs an area of 4 sq.m. of the ground inside the tent. If height of the tent is 18m, find the volume of the tent.

 10

In a field, dry fodder for the cattle is heaped in a conical shape. The height of the cone is 2.1m. and diameter of base is 7.2 m. Find the volume of the fodder. if it is to be covered by polythin in rainy season then how much minimum polythin sheet is needed?