Question

please see question number 3 in the image and solve it with rough work .

Answer 1

Let the sides be 4x and 3x.
Area is
$4x \times 3x = 1728 \\ {x}^{2} = 144 \\ x = 12$
Therefore sides are 3×12 = 36 m and 4×12 = 48 m
Perimeter is
$2 \times (36 + 48) = 168 \: m$
Cost of fencing is
$168 \times 30 = rs. \: 5040$