The piece that young Marty indulges in will be one-eigth the area of the entire cookie, since there are 8 equal pieces.
What is the area of the entire cookie cake?
The area of a circle is π*r²
The diameter is 16 inches, so the radius is 8 inches.
Area = π * 8²
Area = 64 π in²
The entire cookie has an area of 64 π in².
To find the area of Marty's piece, divide this number by 8:
64 π in² ÷ 8 = 8 π in²
Answer is B