Question

an athlete runs around a circular park 10 times .if the diameter of park is 280 m,find the distance covered by the athlete in km..

Answer 1

see... diameter of park = 280 m
so, radius = 280/2= 140 m
length of circumference = 2π×r
                                       = 2×(22/7)×140
                                       =880 m
now,
he runs 10 times around the park, so total distance covered by him = 10 ×880 = 8800 m
1 km = 1000 m
so, 8800 m = 8.8 km

Answer 2

circumference= 2piR
radius=diameter/2=140m
C=2×22/7×140
=880m
880×10
=8800m
=8800/1000
=8.8 km.