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Mathematics

Each side of a square formed by a wire is 14 cm. The area of the circle that can be formed by this wire is :

  1. 144 cm2

  2. 154 cm2

  3. 164 cm2

  4. 249.45 cm2

Mensuration

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Answer

Given,

Each side of a square formed by a wire is 14 cm.

Total length of wire = Perimeter of square = 4 × 14 = 56 cm.

The circle formed with the wire will be having the circumference = 56 cm.

Let radius of circle be r cm.

2πr = 56

r = 562π=28π\dfrac{56}{2π} = \dfrac{28}{π}

Area of circle = πr2

=π×(28π)2=π×28π×28π=28×28π=28×28227=28×28×722=249.45 cm2= \pi \times \left(\dfrac{28}{π}\right)^2 \\[1em] = \pi \times \dfrac{28}{π} \times \dfrac{28}{π} \\[1em] = \dfrac{28 \times 28}{π} \\[1em] = \dfrac{28 \times 28}{\dfrac{22}{7}} \\[1em] = \dfrac{28 \times 28 \times 7}{22} \\[1em] = 249.45 \text{ cm}^2

Hence, option 4 is the correct option.

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