The perimeter of the rectangle is 30cm. Find the area of the rectangle if the length of one of the sides is 6 cm.

It is known from the condition that the perimeter of the rectangle is 30 cm. In order to find the area of the rectangle, if the length of one of the sides is 6 cm, we must find the width of the rectangle.

To do this, we will compose and solve the equations using the formula for finding the perimeter of a rectangle.

P = 2 (a + b), substitute the values and calculate:

2 (6 + x) = 30;

6 + x = 30: 2;

6 + x = 15;

x = 15 – 6;

x = 9 cm width of the rectangle.

To find the area of a rectangle, apply the formula:

S = a * b = 9 * 6 = 54 cm2.

Answer: 54 cm2.



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