The total surface area of this cone is 21π square feet.
What is the total surface area of the cone?
The total surface area of the cone is given by the following formula;
[tex]\rm Surface \ area=\pi r(r+l)[/tex]
Where h denotes the height of the cone and r is the radius and l is the slant height.
The radius of the cone = 3
The height of the cone = 4
Substitute all the values in the formula
[tex]\rm Surface \ area=\pi r(r+l)\\\\\rm Surface \ area=\pi 3(4+3)\\\\\rm Surface \ area=3\pi \times 7\\\\\rm Surface \ area=21\pi[/tex]
Hence, the total surface area of this cone is 21π square feet.
Learn more about the surface area here;
https://brainly.com/question/20759327
#SPJ2