What I did was find the area of the figure as if it were a regular square.
Area = Length x Width
Area = 12 x 20
Area = 240
Then I find the area of the cut out piece, which happens to be a right triangle.
Area = 1/2(length x width)
Base/width = 20 - 14
Base/width = 6
Length = 12 - 10
Length = 2
Area = 1/2(2 x 14)
Area = 1/2(28)
Area = 14
Now subtract
240 - 14 = 226
226 should be your answer
Please correct me if I'm wrong xP
Circle above 6 than an arrow going behind 6