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

The perimeter of a rectangle is equal to the sum of all its sides P = a + b + c + d. Since the opposite sides of the rectangle are equal, then P = 2 * a + 2 * b. Substituting the known values of the perimeter and one of the sides, we can find the length of the second side: 30 = 2 * 6 + 2 * a, 30 = 12 + 2a, 2a = 30 – 12, 2a = 18, a = 18: 2, a = 9 meters. The area of the rectangle is equal to the product of length and width: S = a * b. Substitute the values of the sides 6 cm and 9 cm into the formula and find the value of the area: S = 6 cm * 9 cm = 54 cm square.