Question

If the ratio of area of circle is 4:9. then what is the ratio of circustance of these circle

Answer 1

let the radius of first circle be r and that of second circle be R
area of first circle=πr²
that of second circle=πR²
their ratio=πr²/πR²=4/9
r²/R²=4/9
r/R=√4/√9=2/3
r=2,R=3
circumference of first circle=2πr=2π×2
that of second circle =2πR ,2π×3
their ratios =2π2/2π3=2/3=2:3
hope it helped you

Answer 2

Let the radius smaller circle is r
and radius of larger circle is R
now area of small circle is (a) = πr²
area of larger circle is(A) = πR²

ATQ
a:A = 4:9
r²/R² = 4/9
=> r/R = 2/3

now
circumfrence of smaller circle is (c)= 2πr
larger circle is (C) = 2πR
now
c:C = 2:3
Ans