The answer is 63,800 mi²
hoped this helps
Needing to find the circumference of a circle you you find that you need to use the equation C=2 π R
C= 28.26
this is how much fence they would need around the garden approximately.
Remember property of exponents

add exponents of same base
ok so
50,000 is 5 times 10^4
so
50000 times 10^15=
5 times 10^4 times 10^15=
5 times

=
5 times 10^19
It is the third option: {1, 2, 3}