Question

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

Answer 1

Answer:

46 cm

Step-by-step explanation:

because 2×radius and 22+1=23

Answer 2

Given :-

• The area of a circle is increased by 22 cm when its radius is increased by 1 cm $.$

To find :-

• What is the original radius of the circle ?

Solution :-

Let the original radius be r cm.

then,

As per the question

⇒ π × [ ( r + 1 )² - r² ] = 22

put the value of π = 22/7

⇒ 22/7 × [ ( r + 1 + r ) ( r + 1 - r ) ] = 22

⇒ 2r + 1 = 7

⇒ 2r = ( 7 - 1 )cm

⇒ 2r = 6cm

⇒ r = 6/2 cm

⇒ r = 3cm.

hence, the original radius of the circle is 3cm.

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Extra shots :-

• Volume of cone ↠1/3 πr²h

• Volume of sphere ↠4/3 πR³

• Volume of cube ↠ (Side)³

• Volume of cylinder ↠ πr²h

• Volume of Cone ↠ ⅓ × πr²h

• T.S.A of Cube ↠ 6 × (Side)²

• T.S.A of Cylinder ↠ 2πr² + 2πrh

• L.S.A of Cube ↠ 4 × (Side)²

• L.S.A of Cylinder ↠ 2πrh

• L.S.A of Cone ↠ πrl

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