Answer:
208 cm²
Step-by-step explanation:
First, you take the area of the whole rectangle, to do this you simply multiply 30 by 15, meaning that the big rectangle’s area is 450 cm².
Then, you take the area of the small rectangle (the unshaded one), to do this, you simply figure out the sides (they end up being 11 cm and 22 cm, you can find this out through subtracting) and to find the area of this rectangle, you multiply 11 by 22, which gives you 242 cm²
Now all that is left to do is to subtract the unshaded area by the whole rectangles area to find the shaded part! This will look like this: 450-242= 208 cm²