Answer:
5 cm
Explanation:
First, let's find the perimeter of the rectangle.
The perimeter of a rectangle is:
p=2l+2w
In this rectangle, we know that the length is 7 centimetres and the width is 3 centimetres.Therefore, we can substitute 7 in for l and 3 for w.
p=2(7)+2(3)
Multiply 2 and 7
p=14+2(3)
Multiply 2 and 3
p=14+6
Add 14 and 6
p=20
We know the perimeter of the rectangle is 20 centimeters. We also know that the perimeter of the square is equal to the perimeter of the rectangle.
The perimeter of a square is:
p=s+s+s+s or p=4s
We know that the perimeter of the square is equal to the rectangle. The rectangle's perimeter is 20. Therefore, we can substitute 20 in for p.
20=4s
Now, we want to find what the side length is. We have to get s by itself. 4 and s are being multiplied. To reverse this, divide both sides by 4.
20/4=4s/4
20/4=s
5=s
The side length of the square is 5 centimeters.