Question

I can't find the surface area because I have no clue where to find the radius

Answer 1

You are told the circumference of the sphere. The circumference is the length of the circle around the widest part. You know the formula for the circumference of a circle in terms of radius, so you can find the radius of the sphere.

C = 2πr
496.12 yd = 2*3.14*r
(496.12 yd)/(2*3.14) = r = 79 yd

Then the surface area of a sphere is given by ...
A = 4πr^2
A = 4*3.14*(79 yd)²
A = 78,386.96 yd²


_____
You can also find the area of a sphere in terms of its circumference.
A = C²/π
A = (496.12 yd)²/3.14 = 78,386.96 yd² . . . . same as above.

(The surface area in your problem statement, 3117.25 yd², corresponds to a sphere with a circumference of about 98.94 yd. The circumference given in the problem statement is almost 5 times that, which is why the area is almost 5²=25 times the area in your problem statement. This is a good one to ask your teacher about.)