The width of the rectangle is 90 cm and its area is 180 dm2. What is the perimeter of this rectangular?

Let’s convert centimeters to decimeters to switch to a unified measurement system:

10 cm = 1 dm,

90 cm = 9 in.

The area of a rectangle is calculated by the formula S = a • b, where a is the length of the rectangle, b is the width of the rectangle. From here you can find the length of the rectangle: a = S / b.

We get a = 180/9 = 20 (dm) – the length of the rectangle.

The perimeter of a rectangle is the sum of the lengths of all its sides, i.e.

p = a + b + a + b = 2 • (a + b).

We get p = 2 • (20 + 9) = 2 • 29 = 58 (dm).

Answer: the perimeter of the rectangle is 58 dm.