The area of a circle is increased by 22 cm its radius is

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The area of a circle is increased by 22 cm its radius is increased by 1 cm. The original radius of the circle is

Using Rule 14,
Let the original radius be r cm.
According to the question,
π(r + 1)² – πr² = 22
⇒ π(r² + 2r + 1–r²) = 22

⇒ (2r + l) ×	22	= 22
	7

⇒ 2r + l =	22 × 7	= 7
	22

⇒ 2r = 7 - 1 = 6 ⇒ r =	6	= 3 cm.
	2