The width of the rectangle is 48 cm, which is three-sixteenths of its pyremitre. Find the length of the rectangle.

1. There is a rule: to find a number by its part, it is necessary to divide this part of the number by a fraction equal to this part.

2. Let us calculate the perimeter P of a rectangle if, according to the condition of the problem, its width a, equal to 48 cm, is 3/16 of its perimeter.

P = 48 cm: 3/16 = 48: 3 * 16 = 256 cm.

3. Determine what is the length b of the rectangle using the formula for the perimeter.

P = 2 * a + 2 * b;

b = (P – 2 * a): 2 = (256 cm – 2 * 48 cm): 2 = (256 cm – 96 cm): 2 = 160 cm: 2 = 80 cm.

Answer: The length of the rectangle is 80 centimeters.