To find the area of a rectangle, the area equation is A= length X width. So you have to take all the rectangles and add the areas together to get the whole area of the polygon.
So the left rectangle is 12 X 4 = 48.
the middle bottom rectangle is 14 X 6= 84.
the top right triangle, is 5 X 4= 20.
So then you add all of the areas together.
48+84+20= 152.
Area of the Polygon= 152 cm