Because the areas of the two triangles are the same, the overlapping parts must be the same, so the areas of the non-overlapping parts of the two triangles are also the same, just multiply by two. Look at that white triangle. Its non-overlapping part is a trapezoid, the upper base is (1 1.6-4)cm=7.6cm, the lower base is 1 1.6cm, and the height is 2cm, so its area is: (7.6+1.