Answer:
To find the area of the stage, we need to use the formula for the area of a trapezoid, which is:
Area = (a + b) * h / 2
where a and b are the lengths of the parallel sides, and h is the height (or distance between the parallel sides).
In this case, we know that:
a = 80 feet
b = 50 feet
h = 40 feet
Plugging these values into the formula, we get:
Area = (80 + 50) * 40 / 2
Area = 130 * 20
Area = 2600 square feet
Therefore, the area of the stage is 2600 square feet.