The top and bottom sides are each 50 cm, and the right and the left side of the rectangle is 50cm. Which means, if you multiply 50 by two, and 10 by two, then add them together, you will get the perimeter of 120 cm. Formula of Perimeter: Length + Length + Width + Width = Perimeter
I found the answer by multiplying the width (10cm) by 2. I then got 20. After that I subtracted 20 from the perimeter and got 100. Then, I divided that by 2 and got the length of each of the sides which is 50cm.
