The length of the rectangle is 12 cm, and the width is one third of its length.

The length of the rectangle is 12 cm, and the width is one third of its length. Find the perimeter and area of the rectangle.

Brief notation of the problem condition:
Rectangle;
a = 12 cm;
b = 1/3 of the length;
P =?;
S =?
Decision:
1) Find the width of the rectangle, which is 1/3 of the number 12.
To find some part of a number, you need to multiply this number by the fraction expressing this part.
12 * 1/3 = 4 (see);
2) The perimeter of a rectangle is equal to twice the sum of its width and length, which can be written in the form of the formula:
P = 2 * (a + b);
P = 2 * (4 + 12) = 2 * 16 = 32 (cm.);
3) The area of the rectangle is equal to the product of the length and width, which can be written in the form of the formula:
S = a * b;
S = 12 * 4 = 48 (sq. Cm.)
Answer: P = 32 cm.; S = 48 sq. cm.