how do i define variable and write equation for...

The perimeter of a square equals 4 time the length of a side?

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P = 4s

To define a variable and write an equation for the perimeter of a square, follow these steps:

Step 1: Define a variable:
Choose a letter or symbol to represent the length of a side of the square. Let's say we choose "s" to represent the length of a side.

Step 2: Write the equation:
The equation for the perimeter of a square is given by "P = 4s", where P represents the perimeter and s represents the length of a side.

By substituting the formula for the perimeter (4s) into the equation, we have:
P = 4s

Now, whenever you want to find the perimeter of a square, you can substitute the length of a side into this equation and solve for P.