Question

The ratio of circumference to the area of a circle of radius r units is​

Answer 1

GIVEN :-

• Radius of circle = r units.

TO FIND :-

• The ratio of circumference to the area of a circle.

SOLUTION :-

$\\ : \implies \displaystyle \sf \: \frac{Circumference}{Area} = \frac{2\pi r}{\pi r ^{2} }$

$: \implies \displaystyle \sf \: \frac{Circumference}{Area} = \frac{2\pi r}{\pi \times r \times r }$

$: \implies \displaystyle \sf \: \frac{Circumference}{Area} = \frac{2}{r}$

$: \implies \underline{ \boxed{ \displaystyle \sf \: {Circumference}:{Area} = 2:r}}$

EXTRA INFORMATION :-

• Area of circle = πr².
• Circumference of circle = 2πr.
• Perimeter of semi circle = πr + 2r.
• Area of semi circle = (πr²)/2

Answer 2

Answer:

Given :-

• Radius = r

To Find :-

Ratio of circumference and area

Solution :-

Let the Circumference be C and Area be A

C/A = 2πr/πr²

C/A = 2 × π × r/ π × r × r

C/A = 2 × r/ r × r

C/A = 2/r

Hence :-

Ratio => 2:r