Question

Find the circumference of a circular track with a diameter of 21 km​

Answer 1

Step-by-step explanation:

using formula,

circumference circumference of a circle= 2πr

here, diameter is equal to 21 kilometre

so radius= 21/2 i.e. r = D/2

i.e.

circumference circumference of a circular track = 2×22/7×21/2

22/7×21

462/7

66km

or

21πkm

Answer 2

HERE IS UR ANSWER DEAR,

diameter = 2r = 21 km

radius = r. = 21 /2km

=circumference of circle

$= 2\pi \: r$

$= 2( \frac{22}{7} )( \frac{21}{2})$

$= \frac{22 \times 21}{7}$

$= 66$