It is given that
Diameter of the cone = 24m
Radius of the cone = 24/2 = 12m
Slant height of the cone = 21m
We know that
Total surface area of a cone = πr (l + r)
By substituting the values
Total surface area of a cone = (22/7) × 12 (21+12)
On further calculation
Total surface area of a cone = (22/7) × 12 × 33
So we get
Total surface area of a cone = 1244.57 m2
Therefore, the total surface area of a cone is 1244.57 m2.
