Question

the ratio of radii of two circles is 3:5.find he ratio of their circumference
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Answer 1

$\huge\mathbb{SOLUTION:-}$

• Given that the ratio of radii of 2 circles
• => 3:5

• We have. to find the ratio of their circumference

Now :-

$\bf\underline{\underline{According\:To\: Question:-}}$

• Let the radii be x
• 3x and 5x

$\boxed{\sf{Circumference\:of\:circle=2\pi r}}$

$\sf\implies Circumference\:of\:circle_1=2\times \pi\times 3x$

• Now the circumference of 2nd circle

$\sf\implies Circumference\:of\:circle_2=2\times \pi\times 5x$

$\boxed{\sf{Ratio=\frac{Circumference\:of\:circle_1}{Circumference\:of\:circle_2}}}$

$\sf\implies Ratio=\frac{2\pi 3x}{2\pi 5x}\\ \\ \sf\implies Ratio=\frac{\cancel{2\pi x}3}{\cancel{2\pi x }5}\\ \\ \sf\implies Ratio= \frac{3}{5}\\ \\ \tt\implies Ratio\:of\: circumference=3:5$

$\boxed{\sf{\purple{Ratio\:of\: circumference=3:5}}}$