Question

what is the formula of a circamfrance in area

Answer 1

The formula for circumference and area is different for different polygons and shapes.
For example
For square
Circumference = 4*each side
Area = side *side

For rectangle
Circumference = 2 (length + breadth)
Area = length * breadth

For triangle
Circumference = Sum of all three sides 
Area = 1/2 * base * height

For circle
Circumference = 2*π * radius
Area = π(radius)².

Hope my answer helps you.

Answer 2

hye

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circumference is only apllicable for circle

like square has perimeter ,circumference is the distance around it 

the actual formula is 

c = 2πr 

where π =22/7 and r = radius

examole 1 :find the circumfernece ,whose radius is 14 cm

=>since c = 2πr  and radius is 14

=>2 × 22/7 ×14

=>88 cm

now how to find circumfernece when diameter is given?

first we find the radius

diameter = 2  × r

=>radius = d /2

and then we aplly  c= 2πr

now how to find circumfernece when area is given?

since area of circle =  π × r ²

                                  = 22/7 × r²

we do r² = area   × 7/22 

we get the answer .lets keep as x

then r ² = x

=>radius  = √x

then we take this radius and apply

=>c = 2πr

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hope it helps u............