Question

11. 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 kilometres.
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Answer 1

Given :-

• diameter of the park = 280m
• number of rounds = 10 rounds

To Find :-

• distance covered by the athlete in Km

Solution :-

we have,

diameter = 280 m

then,

$\bold{radius = \cancel \frac{280}{2} } \\ \\ \bold{ \implies 140 \: m} \: \: \: \: \: \:$

and we know that,

$\boxed{ \bold{circumference \: of \: circle = 2\pi r}}$

$\bold{ : \implies 2 \times \frac{22}{ \cancel7} \times \cancel{140} } \\ \\ \bold{: \implies 2 \times 22 \times 20 } \: \: \: \: \\ \\ \bold{: \implies 880 \: m} \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

so, the distance of one round of the park = 880 m

now,

$\bold{10 \: rounds = 880 \times 10} \\ \\ \bold{: \implies 8800 \: m} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies 8.8 \: km } \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

hence, distance covered by the athlete is 8.8 Km