If areas of three circles are in ratio 4:9:25, what is the ratio of their radii?

To find the ratio of the radii of the three circles whose areas are in the ratio of 4:9:25, we start by using the relationship between the area of a circle and its radius.

The area A of a circle is given by the formula:

A = πr²

where r is the radius of the circle. Therefore, if we have three circles with areas in the ratio 4:9:25, we can denote their areas as:

  • A₁ = 4 (for the first circle)
  • A₂ = 9 (for the second circle)
  • A₃ = 25 (for the third circle)

Next, we can express the radii in terms of their respective areas:

  • For the first circle: A₁ = πr₁² → r₁² = A₁ / π → r₁ = √(A₁ / π)
  • For the second circle: A₂ = πr₂² → r₂² = A₂ / π → r₂ = √(A₂ / π)
  • For the third circle: A₃ = πr₃² → r₃² = A₃ / π → r₃ = √(A₃ / π)

Now, to find the ratio of the radii, we can find the ratios of r₁, r₂, and r₃ directly from the areas:

r₁ : r₂ : r₃ = √(A₁) : √(A₂) : √(A₃) = √(4) : √(9) : √(25) = 2 : 3 : 5

Thus, the ratio of the radii of the three circles is 2:3:5.

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