Question

if a wire is bent into shape of a square , then the area enclosed by the square is 81 cm . when the same wire is bent into a semicircle the area is

Answer 1

Area Of square a^2 = 81 ====> a = 9
The wire when bent in a form of Square i.e. the total perimeter of the square

Therefore,Perimeter of Square = 4a = 4*9 = 36 which is total length of the wire
the wire which is bent in the form of semicircle forms circumference of semicircle

therefore circumference is 22/7r+2r = 36 where 'r' is radius
(22+14)*r/7 = 36

r = 7 cm

Therefore area of semicircle is {(22/7)r^2}/2 = (1/2)*(22/7)*7*7

By simplifying 
we get Area of semicircle = 77 cm^2 

Answer 2

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