Question

Find the following ratio:

The ratio of the circumference of circle to area of circle.​

Answer 1

2pir:pirsquare is the answer

Answer 2

$\large\underline{\bold{Solution-}}$

Let the radius of circle be 'r' units.

We know

$\rm :\longmapsto\:Area_{(circle)} = \pi \: {r}^{2}$

and

$\rm :\longmapsto\:Circumference_{(circle)} = 2\pi \: r$

Now,

we have to find ratio of the circumference of circle to area of circle.

So,

$\rm :\longmapsto\:\dfrac{Circumference_{(circle)}}{Area_{(circle)}} = \dfrac{2\pi \: r}{\pi \: {r}^{2} }$

$\rm :\longmapsto\:\dfrac{Circumference_{(circle)}}{Area_{(circle)}} = \dfrac{2}{r}$

$\bf\implies \:Circumference_{(circle)} : Area_{(circle)} = 2 : r$

Additional Information :-

1. Circumference :- The boundary of the circle is known as the circumference

2. Diameter :- The line that passes through the centre of the circle and touches the two points on the circumference is called the diameter and it is denoted by the symbol “D”

3. Radius :- The line from the centre “O” of the circle to the circumference of the circle is called the radius and it is denoted by “r”

4. Arc :- Arc is the part of the circumference where the largest arc is called the major arc and the smaller one is called the minor arc.

5. Chord :- The straight line that joins any two points in a circle is called a chord. Diameter is the largest chord in a circle.