To solve this problem, you can split the shape into a triangle and a parallelogram.
You can do this by imagining/drawing a line from point A to point C>
Now you can work out the area of triangle ACB
1/2 x b x h
1/2 x 5 x 3
= 7.5
Now work out the area of the parallelogram ACDE
b x h
5 x 3 = 15
Add the areas together and then you have the answer
7.5 + 15 = 22.5