Calculate the area of a rectangle with a perimeter of 120dm, the width of which is 1 \ 10, of the perimeter.

Calculate the area of a rectangle with a perimeter of 120dm, the width of which is 1 \ 10, of the perimeter. What part of the length of this rectangle is its width.

By the condition of the problem, it is known that the perimeter of some rectangle is 120 decimetres.

Let’s calculate what its width is equal to, given that it is 1/10 of the perimeter:

120 * 1/10 = 12 decimeters.

Let’s calculate the length of the rectangle:

P = 2 * (a + b);

a = P / 2 – b;

a = 120/2 – 12 = 60 – 12 = 48 decimeters.

Let’s determine what the area of the rectangle is equal to:

S = a * b;

S = 48 * 12 = 576 dm².

Let’s determine how much the width of this rectangle is from its length:

12/48 = 1/4 of the length.