Answer:
10m
Explanation:
Perimeter means adding up all of the sides of a shape.
One property of a square is that all lengths of a square are the same.
We also know squares have 4 sides.
Lets set up an expression to solve the length for each side with variable S representing the length of a side:
4 * S = 40
Divide each side by 4:
S = 10
Therefore, each side of the square has a length 10m