The expansion of the cone is a fan. If we want to find the surface area of a cone, we must also know how many degrees the central angle of this sector is. If we know the central angle, we can find out the surface area of the cone.

If the degree of the central angle is known, the area is as follows:

The surface area of the cone = the bottom area+the square of the length of the hypotenuse of the cone x∏x (the degree of the cone /360).

Bottom area = square of bottom radius xω

Cone surface area formula:

S =1/2 (l * r) =1/2 (2pai * r * r) (r is the bottom radius and r is the cone radius).

I hope you can be satisfied with my answer! thank you