Question

find the circumference of a circle whose diameter is 4.2 centimetre​

Answer 1

Diameter of circle is 4.2

Therefore ' radius= 4.2/2

Cicrcumfrence=2πr

=2×22/7×4.2/2

=2×22/7×42/2×10

=2×22×6/20

=22×6/10

=11×3

=33cm

Okay

Answer 2

$\underline{\underline{\underline{\underline{\mathfrak{\blue{ \:\:\: Given:-\:\:\:}}}}}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• The diameter of the circle is 4.2 cm.

______________________

$\underline{\underline{\underline{\underline{\mathfrak{\blue{ \:\:\: Find \: out:-\:\:\:}}}}}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• The required circumference of the circle = ?

______________________

$\underline{\underline{\underline{\underline{\mathfrak{\green{ \:\:\: Solution:-\:\:\:}}}}}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\footnotesize\bold{\underline{\underline{\sf{\red{Given\:That:-}}}}}$

• Diameter of the circle is 4.2 cm.

$\footnotesize\bold{\underline{\underline{\sf{\red{Therefore:-}}}}}$

• Radius of the circle = 2.1 cm

$\sf \: Circumference = 2\pi \: r \\ \\ \leadsto\sf \: Required \: Circumference = 2 \times \dfrac{22}{ \cancel7} \times \cancel{2.1} \\ \\ \leadsto\sf \: Required \: Circumference =2 \times 22 \times 0.3 \\ \\ \leadsto\sf \: Required \: Circumference =44 \times 0.3 \\ \\ \leadsto\sf \: Required \: Circumference =\large{\boxed{\bf\purple{13.2 \: cm }}}$

______________________

$\underline{\underline{\underline{\underline{\mathfrak{\pink{ \:\:\: AnswEr:-\:\:\:}}}}}}$

• The required circumference of the circle is 13.2 cm.