The width of the rectangle is 5 cm, the length is 9 cm. The length was increased by 2 cm.

The width of the rectangle is 5 cm, the length is 9 cm. The length was increased by 2 cm. How many centimeters will the perimeter of the rectangle increase?

The perimeter of a rectangle is the sum of the lengths of all its sides. Since in a rectangle the opposite sides are equal, then P = 2 * (a + b), where a is the length, b is the width. Knowing that the width is 5 cm and the length is 9 cm, we calculate the perimeter of the rectangle.
P = 2 * (5 + 9) = 2 * 14 = 28 cm.
Let’s increase the length by 2 cm.
a = 9 + 2 = 11 cm.
We calculate the perimeter of a rectangle with sides of 5 cm and 11 cm.
P = 2 * (5 + 11) = 2 * 16 = 32 cm.
Let’s calculate how many centimeters the perimeter has increased.
32 – 28 = 4 cm.
Answer: 4 cm.