The perimeter of a square is expressed using P = 4a, where a is the length of one side and P is the perimeter. This can also be written as P = a + a + a + a (meaning: side + side + side + side).
In this question, a = 10 and P = 40.
P = 10 + 10 + 10 + 10 = 40 inches.
Alternatively, the equation would be 40 = 4(10).
Similar to the above equations, a square with (proportional) 6 inch sides means P = 4(6), which then simplifies to P = 24. The perimeter of this square would be 24 inches.
P = 6 + 6 + 6 + 6 = 24 inches.
