perimeter of rectangle = 20+20 +15+15 = 70 yards = 70*3 = 210 feet
210/5 = 42 seconds
Courtney walks it in 42 seconds
the diagonal = 15^s + 20^2 = 225+400=625
sqrt(625) = 25 yards
Natalie walks 20 +15 +25 = 60 yards
60*3 = 180 feet
180 /5 =36 seconds
42 - 36 = 6 seconds faster