Answer: [tex](S_1+S_2)[/tex] square unit.
Step-by-step explanation:
Here, trapezoid, two triangles are formed by the bases and the intersecting diagonal segments.
And, Area of These triangles are [tex]S_1[/tex] squre unit and [tex]S_2[/tex] square unit
Therefore, Total area of the trapezoid formed by these triangles = Sum of the areas of these triangles= [tex](S_1+S_2)[/tex] square unit.