Question

A wire when bent in the form of a square enclose an area 121sq.if the wire was bent in the form of circle, then find the area enclosed by the circle

Answer 1

area of square=121
${a}^{2} = 121 \\ a = 11$
then lenght of wire =4a
=4×11
=44
now in circle
$2\pi \: r = 44 \\ 2 \times 22 \div 7 \times r = 44 \\ r = 7$
$area \: of \: circle = \pi \: {r }^{2} \\ = 22 \div 7 \times 7 \times 7 \\ = 154$