The length of the rectangle is 12 cm, the width is 1 quarter of the length. Find the perimeter of the rectangle.

1) In order to find a part of an integer value, you must divide it by the denominator of the fraction and multiply by its numerator.

Let us find the width of the rectangle, provided that it is длины of the length equal to 12 cm:

12: 4 * 1 = 3 cm.

2) The perimeter of a rectangle whose opposite sides are equal is calculated by the formula:

P = 2a + 2b = 2 * 12 + 2 * 3 = 24 + 6 = 30 cm.