Find the radius of a circle whose perimeter and area are numerically equal.
Given:
Perimeter of circle = Area of circle …… (i)
∵ Perimeter of circle = 2πr and Area of circle = πr2
∴ Using (i), we have
2πr = πr2
2 = 
2 = r or r = 2
Hence, the radius of the circle is 2 cm.
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