Question

The area of the circle is given below; find the diameter.

394.24 sq cm

Answer 1

Area of the circle = 394.24 sq. cm     ...[Given]

Area of the circle = πr²

∴ `394.24 = 22/7 xx r^2`

∴ `r^2 = 394.24 xx 7/22`

∴ `r^2 = (394.24 xx 100)/(1 xx 100) xx 7/22`

∴ `r^2 = 39424/100 xx 7/22`

∴ `r^2 = 1792/100 xx 7`

∴ `r^2 = 12544/100`

∴ `r^2 = 112^2/10^2`

∴ `r = 112/10`    ...[Taking square root of both sides]

∴ r = 11.2 cm

∴ Diameter = 2r

= 2 × 11.2

= 22.4 cm