Question

Find the curved surface area , the total surface area and the volume of a cone if its : 

Height = 15 cm , radius = 8 cm

Answer 1

Height = 15 cm , radius = 8 cm

Curved surface area = `(pir sqrt(h^2 + r^2))`

 = `22/7 xx 8 xx sqrt(15^2 + 8^2)`

= `22/7 xx 8 xx sqrt(289)`

= `22/7 xx 8 xx 17`

= 427.43

Curved surface area = 427.43 cm²

Total surface area = area of circular base + curved surface area

 = `pir^2 + (pir sqrt(h^2 + r^2))`

= `22/7 xx 8 xx 8 + 427.43`

= `201.14 + 427.43`

= 628.57

Total surface area  = 628.57 cm²

Volume = `1/3 xx (pir^2) xx h`

 = `1/3 xx 22/7 xx 8 xx 8 xx 15`

 = 1005.71

Volume of the cone = 1005.71 cm³