The length of the rectangle is 13cm and the width is 8cm. What is the perimeter of the rectangle?

The perimeter of the figure is equal to the sum of the lengths of all its sides. Then for a rectangle:

P = a + b + a + b = 2 * (a + b), where a is the length of the rectangle and b is the width.

Using the above formula and substituting the numerical values for the length and width of the rectangle in the problem statement, we get:

P = 2 * (13 + 8) = 42 centimeters.

Answer: The perimeter of a rectangle with sides of 13 centimeters and 8 centimeters is 42 centimeters.