Since the rectangle is also a parallelogram if its opposite sides are parallel, according to the question it is a parallelogram and the triangle lies between the parallels and on the same base , 

area of triangle = half area or rectangle.
so , area of rectangle = 1/2 * 16 = 8m2
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When a triangle and rectangle lie on the same base and between same parallel lines then the area of triangle will be half of the area of the rectangle.
so , the area of triangle = 1\2area of the rectangle.
area of triangle = 16\2
area of triangle = 8cm²