Question

the ratio of the diameter of 2 circles is4:5find the ratio of their circumference

Answer 1

let the diameter of 1 circle be 4x then their radius be 2x

the radius of 2nd circle is 2.5x

ratio of circumference=2πr/2πr
= 2π×2.5/2π×2
2.5./2
=.5

Answer 2

Answer:

The ratio of the circumference of the two circles is 4:5

Step-by-step explanation:

Given ::- ratio of diameters of two circles - 4:5

To find ::- ratio of the circumference of two circles.

Solution::-

Let the common multiple be x

So, let d₁ = 4x and d₂ = 5x

Now, radius of two circles are

r₁ = 4x/2 r₂ = 5x/2

r₁ = 2x r₂ = 5x/2

Let the ratio of the circumference of two circles be

2πr₁ / 2πr₂

= r₁ / r₂ ( 2π get cancelled)

= 2x / 5x/2

= 2x × 2/5x ( taking reciprocal of denominator)

= 4/5 ( x gets cancelled)

So, the ratio of the circumference of two circles is 4:5

HOPE IT HELPS YOU!!