the perimeter of the square = 40units.
We are told the side of the square = (7+3) units
By summing the values, the side of the square = 10 units.
The perimeter of a square = 4 multiplied by the length.
This is because all sides of a square are equal and a square has are four sides.
Perimeter is the sum of all the sides.

Hence, the perimeter of the square = 40units.