Question

the ratio of the circumference of two circles is 4.9 what is the ratio of their areas​

Answer 1

Answer:

Correct option is

B

16:81

Given that C

1

:C

2

=4:9⇒2πr

1

:2πr

2

=4:9⇒r

1

:r

2

=4:9

We have

A

2

A

1

=

πr

2

2

πr

1

2

=

9

2

4

2

=

81

16

∴A

1

;A

2

=16:81

Answer 2

the radius of circles will be always different . so

Let Radius of two circles be r , R respectively .

so, Given that

(2πr)/(2πR) = 4.9

• 2π gets cancelled

⇒ r/R = 4.9

⇒ r = 4.9R _____eq[1]

so, finding ratio b/w Areas

⇒ (πr²)/(πR²)

• π gets cancelled , from eq1

⇒ (4.9R)²/(R)²

⇒ 4.9R²/R²

• R² gets cancelled

⇒ 4.9

____________________________

• The Ratio b/w the Areas is 4.9