Length of a circle=2πr r=40 m Length of the circular track=2*π*40m=80π m.
The athelete jogs each day 10 laps 1 lap-------------------80π m 10 laps------------- x x=(10 laps * 80π m) / 1 lap=800π m
Calculate how far he jog eache week (5 days). 1 day------------------800π m 5 days---------------- x x=(5 days*800π m)/1day=4000π m=4000m * 3.141592...≈12566,37 m