1) Find the area of circle whose circumference is 37.4 cm.

2)The areas of two circles are in the ratio 4:9.Find the ratio between their circumferences.

bt how 1 sol came plzz tell

Circumference is given 37.4 cm

So 2*pi*r= 37.4

=> r=37.4/(2*pi)

=> r=18.7/pi

Now are is pi*r^2. Place the value of r here = pi*(18.7/pi)^2=(18.7)^2 / pi=111.309

now pi*R^2 / pi*r^2=4/9 This means that R/r=2/3 => 2pi*R / 2*pi*r=2:3