Q10 of 79 Page 229

The radius and height of a right circular solid cone are 7 cm and 24 cm respectively. Find its curved surface area and total surface area.

Given : Radius of cone = r = 7 cm

Height of cone = h = 24 cm


To find : CSA of cone = ?


TSA of cone = ?


Formula : l =


CSA of cone = rl


TSA of cone = r (r + l)


Solution : l = = = = = 25 cm


CSA of cone = rl = × 7 × 25 = 22 × 25 = 550 cm2


TSA of cone = r (r + l) = × 7 (25 + 7) = 22 × 32 = 704 cm2


∴ The curved surface area and total surface area of the right circular cone is 550 cm2 and 704 cm2 respectively.


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