In this example, we are asked to find the perimeter of the trapezoid. The perimeter of a figure is the distance around the figure.
To find the perimeter of the trapezoid, all we have to do is add the lengths of the sides. In this case, we would add 3 + 5 + 3 + 9 = 20 cm.
Therefore, the perimeter of the trapezoid is 20 cm