Answer :
I think I got it
we assume they can see in a circle
20 km in a ll diretions
find area of circle
20km=radius of circle
area=pir^2
area=pi20^2
area=400pi
aproxpi=3.14
area=1256 km^2
about 1256 square kilometers
we assume they can see in a circle
20 km in a ll diretions
find area of circle
20km=radius of circle
area=pir^2
area=pi20^2
area=400pi
aproxpi=3.14
area=1256 km^2
about 1256 square kilometers