KMartinez, this is the solution:
As you can see, we have one figure that we can separate in two rectangles. We need to calculate the area of each rectangle and add them, this way:
Rectangle A:
Length = 9
Width = 4
Area = 9 * 4 = 36 cm²
Rectangle B:
Length = 10 - 4 = 6
Width = 3
Area = 6 * 3 = 18 cm²
Now, we can calculate the total area:
Total area = Area of the rectangle A + Area of the rectangle B
Total area = 36 + 18
Total area = 54 cm²