The perimeter of the rectangle is 54 cm and the length is 10 cm. What is its area?

From the condition it is known that the perimeter of the rectangle is 54 cm, and it is also known that its length is 10 cm.

Before finding the area, we need to find the width of the rectangle. Let’s remember the formula for calculating the perimeter:

P = 2 (a + b).

Substitute the known values and solve the resulting equation in one variable:

2 (10 + b) = 54;

10 + b = 54: 2;

10 + b = 27;

b = 27-10;

b = 17 cm.

Let’s remember the formula for calculating the area and apply it:

S = a * b.

Substitute the values and calculate:

S = 10 * 17 = 170 cm ^ 2.