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If radius of a circle is increased to twice its original length, how much will the area of the circle increase?

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प्रश्न

If radius of a circle is increased to twice its original length, how much will the area of the circle increase?

विकल्प

  • 1.4 times

  • 2 times

  • 3 times

  • 4 times

MCQ
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उत्तर

4 times

Explanation:

Let r be the radius of the circle.

∴ Area of circle = π2

If radius is increased to twice its original length, then radius will be 2r.

Now, area of new circle = π(2r)2 = 4π2 = 4 times of original area

Hence, the area of circle will be increased by 4 times.

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अध्याय 9: Perimeter and Area - Exercise [पृष्ठ २७३]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar Class 7
अध्याय 9 Perimeter and Area
Exercise | Q 30. | पृष्ठ २७३

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