Question

the radius of a circle is increased by 20% its area is increased by​

Answer 1

Answer:

Area will increase by 44%

Step-by-step explanation:

Let r is the initial value of radius.

Then initial value of area = πr²

Radius is increased 20%.

So new radius = (120/100)*r = 1.2r

New area = π(1.2r)² = π*1.44*r² = 1.44πr²

So increase in area = 0.44*100 = 44%

Answer 2

Answer: Suppose radius= 1r

then area. =πr^2

Now. , the new radius is 20% more than previous radius.

i.e. New radius = 1r+ 20%(1r)

= 1r+ 0.2r

= 1.2r

Now,. New area=. π(1.2r)^2

=. π×1.2r×1.2r

[ New area =. 1.44πr^2]

[Previous area= πr^2]

Now ,. Increase in area=.

New area- previous area×100

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Previous area

=. (1.44πr^2. -πr^2) ×100

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πr^2

=. 0.44πr^2×100

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πr^2

=. 0.44×100

Increase in area =. 44%