pls teach me how to start amd solve part (A). thank you very much
is the slant height of the cone.
The formula for the Total Surface Area of a cone is
where is the radius and is the slant height.
Note that is the area of the circular base, so is the curved area.
Since you're told that the curved surface has area and the radius , we have
.
You can find the height using the Pythagorean Theorem.