Answer:

Explanation:
To find the surface area of a cone, one uses the following formula,

Where (r) is the radius of the base of the cone, and (h) is the height of the cone, (
) represents the numerical constant (3.1415...). In order for this formula to work, one needs the height of the cone. This can be found using the Pythagorean theorem. One can form a right triangle with the base's radius, the side length, and height of the cone, then solve for the height of the cone. The Pythagorean theorem states the following,

Substitute,

Simplify,

Inverse operations,

Now one can use the formula to find the surface area of a cone, substitute in the given values, and solve,

Substitute,

