You could break down the shape and then get to the area but there is a better way.
The picture looks like a rectangle with a chunk pulled off it.
Let just imagine that it was a perfect rectangle.
Its dimensions would be 57 by 36 (20+16).
Perfect Rectangle Area = 57x36 = 2052 [tex]cm^{2}[/tex]
Now, let us find the area of the indent and subtract that from the previous area.
Indent Area = 16 x (57-15-15) = 16x27 = 432 [tex]cm^{2}[/tex]
Real Area = 2052 [tex]cm^{2}[/tex] - 432 [tex]cm^{2}[/tex] = 1620 [tex]cm^{2}[/tex]
answer = 1620 [tex]cm^{2}[/tex]
