Question

Find the circumference of a circle whose radius is 21 cm.​

Answer 1

▬▬▬▬ஜ۩۞۩ஜ▬▬▬▬

$\huge \blue{q} \red{u} \green{e} \pink{s} \purple{t} \orange{i}o\red{n}$

Find the circumference of a circle whose radius is 21 cm.

Step-by-step explanation:

$\huge\blue{s} \red{o} \green{l} \pink{u} \purple{t} \orange{i} \red{o}n$

$Given, \\ Radius \: of \: the \: circle \: = 21 cm$

$As \: we \: know, \\ Circumference \: of \: the \\ circle = 2πr$

$Therefore, \\Circumference \\ = 2 ×\frac{22}{7} × 21 \\ = 2 × 22 × 3 \\ = 132$

$So, \\ the \: circumference \: of \: a \\ circle \: with \: radius \\ 21cm \: is \: 132 cm$

▬▬▬▬ஜ۩۞۩ஜ▬▬▬▬

Answer 2

• Given

• Radius of a circle = 21 cm

• To find

• Circumference of a circle

• Explanation

• We have the radius of a circle. By using the formula to find circumference and substituting the values in it we will find it.

Some formulae

• Radius = Diameter/2
• Diameter = 2 × Radius
• Circumference of a circle = 2πr
• Area of circle = πr²

• Solution

Circumference = 2πr

where,

• r = Radius of circle
• Take π = 22/7

Substituting the given values,

⇒ 2 × 22/7 × 21

⇒ 132 cm

• Circumference of circle = 132 cm