Calculate the perimeter of a rectangle if its area is 140 cm2 and its length is 20 cm.

Decision:
The area of a rectangle is equal to the product of its length and width.
Knowing the area and length of the rectangle, we find the width of the rectangle: 140/20 = 7
7cm – rectangle width
The perimeter of a rectangle is equal to the sum of the lengths of all its sides. Knowing the width and length of the rectangle, we find its perimeter:
P = 20 * 2 + 7 * 2 = 40 + 14 = 54
54cm – rectangle perimeter
Answer: 54cm



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