Question

the ratio of radii of two wheels is 4:5 find the ratio of their circumference.​

Answer 1

Let the radii be r₁ and r₂ respectively,

and its given that r₁: r₂ = 4: 5

Let the symbol of proportionality be x,

then  r₁ = 4x and r₂ = 5x

Now, the circumference of a circle = $2\pi r$

Let the circumference of the two circles be C₁ and C₂

To find: C₁: C₂

$\frac{C_{1}}{C_{2}}=\frac{2\pi r_{1}}{2\pi r_{2}}\\\implies \frac{C_{1}}{C_{2}}=\frac{4x}{5x}\\\\\therefore {C_{1}}:{C_{2}} = 4: 5$

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