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If the radius of a circle is tripled, the area becomes - Mathematics

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प्रश्न

If the radius of a circle is tripled, the area becomes ______.

पर्याय

  • 9 times

  • 3 times

  • 6 times

  • 30 times

MCQ
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उत्तर

If the radius of a circle is tripled, the area becomes 9 times.

Explanation:

Let r be the radius of a circle.

∴ Area of circle = πr2

If radius is tripled, then new radius will be 3r.

∴ Area of new circle = π(3r)2 = 9π2 = 9 times of original

Hence, the area of a circle becomes 9 times to the original area.

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पाठ 9: Perimeter and Area - Exercise [पृष्ठ २७५]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 7
पाठ 9 Perimeter and Area
Exercise | Q 36. | पृष्ठ २७५

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