96cm
The area of the rectangle is 72 (6 x 12)
The base of the left triangle is six and the height is six. Base x height is 36. 36/2 is 18.
The base of the right triangle is 2 and the height is 6. 6 x 2 is 12. 12/2 is 6.
6 plus 18 plus 72 is 96, which is the final answer.