The ratio of radius of two circles is 4:7,then the ratio of their circumference is
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The ratio between circumference of two circles is 4 / 7. We know that the circumference of circle is 2πr where r is the radius of the ... So ratio 4:7.
Answer:
The circumference of two circles has a ratio of 4:7. What will be the ratio of their areas?
The ratio between circumference of two circles is 4 / 7.
We know that the circumference of circle is 2πr where r is the radius of the circle
The circumference of first circle= 2πr1
The circumference of second circle= 2πr2
The ratio between circumferences
2πr1 / 2πr2 = 4 / 7
r1 / r2 = 4 / 7…Eq..1
We know the area of circle is πr^2 where r is the radius of the circle. The radius of two circles are r1 and r2
The area of first circle = πr1^2
The area of second circle = πr2^2
The ratio between areas of two circles
πr1^2 / πr2^2
On simplifying the equation πr is deducted with πr.
r1^2 / r2^2
In Eq..1 we have the value of r1 / r2 of two circles as 4 / 7.
r1 / r2 = 4/7
r1^2 / r2^2 = 4^2/7^2
r1^2 / r2^2 = 16 / 49
Thus ratio between the areas of two circles is 16 / 49
Answer : The ratio between the areas of two circles is 16 / 49