The perimeter of the rectangle is 80 cm. 60% of this perimeter is the sum of the lengths

The perimeter of the rectangle is 80 cm. 60% of this perimeter is the sum of the lengths of the rectangle. What is the width of the rectangle.

Since the opposite sides of the rectangle are equal. Therefore, the sum of its lengths is 2 equal sides. Let us find this value by making a proportion, provided that it is 60% of the perimeter of such a figure, equal to 80 cm:

x = 60%.

80 cm = 100%.

Let’s write the equation, acting according to the “cross” rule and find the value of the variable:

x = 60 * 80: 100 = 4800: 100 = 48 cm.

Express the width from the perimeter formula:

P = 2a + 2b.

Accordingly: b = (P – 2a): 2 = (80 – 48): 2 = 32: 2 = 16 cm.