Find the surface area of a sphere with a great circle that has an area of 49 π square miles.

A. 225π mi2

B. 196 π mi2

C. 126 π mi2

D. 343 π mi2

The answer is B. 196 π mi2

(1) Find radius r:

The area of the circle is:

A = r²π

A = 49π mi²

49π = r²π

49 = r²

r = √49 = 7 mi

(2) Find the surface area of the sphere.

The surface area of the sphere is:

A = 4πr²

r = 7 mi

A = 4π * 7²

A = 4π * 49

A = 196π mi²