Total Surface Area of Cone
Total Surface Area of Cone:
Total surface area of cone = Curved surface area + Area of the base
Illustration: Find the total surface area of a cone, if its slant height is 12 m and the radius of its base is 9 m.
Solution: We know that the total surface area S of a right circular cone of radius r and slant height l is given by S= .
Here, r = 9 m and l = 12 m.
Illustration: The total surface area of a cone is If the slant height of the cone be 8 cm, find the radius of the base.
Solution: Given: Area of the curved surface of a cone is and slant height of the cone = 8 cm
Also, we know that the Total surface area of the cone
As l = 8, hence we have
As r cannot be negative, So we must have
Hence, radius of the base is