If two cones with same base and hight are joined together along their bases, then the shpae so formed is look like as figure shown.
ltbtgt Given , that, radius of cone , r= 8 cm and height of cone , h= 15 cm,
So, surface area of the shape so fromed
= Curved area of the cone + Curved surface area of second cone
= 2.surface area of cone " "[Since, both cone are indentical ]
`= 2 xx pirl = 2xx pi xx r xxsqrt(r^(2) + h^(2))`
` = 2xx (22)/(7) xx8 xx sqrt((8)^(2) + (15)^(2))`
`= (2xx22xx8 xx sqrt(16 +225))/(7)`
` =(44 xx 8 xx sqrt(289))/(7)`
` = (44xx 8 xx 7)/(7)`
` = (5984)/(7) =- 854.85 cm^(3)`
`= 855 cm^(3)` (approx)
Hence, the surface area of shape so fomed is `855 cm^(2)`.
