To find the area of a trapezoid, you can use the formula:
Area = (1/2)(b1 + b2)h
where b1 and b2 are the lengths of the two parallel bases of the trapezoid and h is the height of the trapezoid.
In this case, b1 = 6 inches, b2 = 10.5 inches, and h = 10.4 inches.
Plugging these values into the formula:
Area = (1/2)(6 + 10.5)(10.4)
Area = (1/2)(16.5)(10.4)
Area = (0.5)(171.6)
Area = 85.8 square inches
Therefore, the area of the trapezoid is 85.8 square inches.