A wire is bent to form a square of area 169 cm2. If the same wire is bent to form a circle, then what is its area (in cm2, to the nearest whole number)? Take
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Correct answer: C
Explanation
The correct answer is option 3 i.e. 215.
Area of the square = a2
⇒ a2 = 169
⇒ a = ± 13
Side of the square = 13 cm
When the wire is bent to form a square and then a circle, the perimeter of both figures will be equal.
4a = 2πr
⇒ 4 × 13 = 2 × 22/7 × r
⇒ r = (13 × 7)/11
Area of the circle = πr2
⇒ 22/7 × (13 × 7)/11 × (13 × 7)/11
⇒ 2366/11
⇒ 215.09 cm2