Question

21. If a wire is bent in the shape of a square, the area of the square is 81 cm2. When
the same wire is bent into the form of a semicircular arc bounded by its diameter,
find the area of the shape so formed. (take π = 22/7)​

Answer 1

let the length of wire be x

side of square will be 1/4

side : x × x = 81

x² = 81

i.e. x=

$\sqrt{81}$

=9

length of wire = 9 × 4 = 36

now by using formula of circle you can find it out