What is the approximate surface area of the sphere if circumference is 37.68?

The surface area of a sphere is A = 4 π R².

Sadly, the question doesn't give you 'R', so you have to

back it out of the circumference.

Circumference = π (diameter)

Divide each side by π : Diameter = circumference / π

Radius = 1/2 diameter: Radius = circumference / (2 π)

Area = 4 π R² =

4 π (circumference/2π) ² =

4 π (circumference) ² / 4 π²

Divide top and bottom by 4π : Area = (Circumference) ² / π

Circumference = 37.68 units

Area = (37.68) ² square units / π =

451.93 square units