A rectangle is a quadrilateral in which opposite sides are parallel and equal to each other, and all corners are straight:
AB = CD;
BC = AD.
The perimeter of a rectangle is the sum of all its sides:
P = AB + BC + CD + AD.
The area of a rectangle is equal to the product of its length and width:
S = a * b, where:
S is the area of the rectangle;
a is the length of the BC rectangle;
b – its width AB.
Since the length of the rectangle is seven times its width, and the area is 28 cm2, we express:
x is the width of the rectangle;
7x – its length;
x * 7x = 28;
7×2 = 28;
x2 = 28/7 = 4;
x = √4 = 2;
AB = 2 cm;
BC = 7 2 = 14 cm.
P = 2 + 14 + 2 + 14 = 32 cm.
Answer: The perimeter of the rectangle is 32 cm.
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