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The circumferences of two circles are in the ratio 2:3. What is the ratio between their areas?
Ratio of circumferences of two circles = 2:3
Let the two circles be C1 and C2 with radii ‘r1’ and ‘r2’.
∵ Circumference of circle = 2πr
∴ Circumference of C1 = 2πr1
and Circumference of C2 = 2πr2
Squaring both sides, we get
Multiplying both sides by ‘’, we get
∵ Area of circle = πr2
Hence, the ratio between the areas of C1 and C2 is 4:9.