Perimeter refers to the total length of the square
square have four equal length sides, thus, if one side is 5/7 units
therefore, 4 sides=5/7×4
=20/7
Yes they should reach the 8.1 mile marker by noon
2 hours equals 6 miles 2.4+6=8.4
if they kept walking for a full 2 hours they would reach the 8.4 mile marker
