pi·18.6^2·123°/360° - 1/2·18.6^2·SIN(123°) = 226.3
9.3 repeating is the answer.
Total hours of hiking is 15.12 miles
Time taken is 6.3 hours
The number of miles hiked per hour would be
Total hours ÷ time taken

=2.4 miles
So Megan has hiked 2.4 miles every hour