Hi there!
In order to find the area of the shaded region, you'll need to calculate the area of the big rectangle as well as the area of the smaller rectangle inside. This way you'll be able to subtract the area of the small rectangle from the area of the big rectangle, which will give you the area of the shaded region!
Step by step:
Area formula :

Area of the big rectangle :

Area of the small rectangle :


So your answer is : The area of the shaded region is

There you go! I really hope this helped, if there's anything just let me know! :)