Question

The perimeter of a square is numerically equal to its area. Find its area.

Answer 1

Let the side of a square be $a$.
The perimeter of a square is numerically equal to its area.
perimeter of a square=$4a$.
Area of square =$a²$
Given
$4a=a²$
or, $a(a-4)=0$
or, $a=4$ [ Since $a\ne 0$]
Area of square $=a²=4\times 4=16$ square units.