There are 2 cones in the picture that are joined together at their base.
The radius (r) of the cone = 10 ft
The height (h) of the cone = 24 ft
Thus, the slant height (l) of the cone =

=

= 26 ft
Now, we have all the values, we can calculate the area.
The surface area of a cone including the base =

But since we only need the area without the base so the surface area =

=

=

That is the area of one cone without the base area.
The area of both the cones =
