10th Class Mathematics Areas Related to Circles Question Bank MCQs - Areas Related to Circles

A steel wire when bent in the form of a square encloses an area of\[121c{{m}^{2}}\]. If the same wire is bent in the form of a circle, then the circumference of the circle is:

A) \[88\,cm\]

B) \[44\,cm\]

C) \[22\,cm\]

D) \[11\,cm\]

Correct Answer: B

Solution :

[b] Let o be the side of square.

\[\therefore \,\,\,\,\,\,\,\,\,\,\,\,{{a}^{2}}=121\,\,\,\,\,\Rightarrow \,\,\,a=11\,cm\]

\[\therefore \] Perimeter of square \[=4a=4\times 11=44cm\]

\[\therefore \] Circumference of the circle = Perimeter of square \[=\text{44 cm}\]