To find the area of the quadrilateral, we can split it into two smaller shapes - a triangle and a parallelogram.
The area of the triangle is (1/2) * base * height.
The base of the triangle is 16 - 10 = 6 inches.
The height of the triangle is 6 inches.
Area of triangle = (1/2) * 6 * 6 = 18 square inches.
The area of the parallelogram is base * height.
The base of the parallelogram is 10 inches.
The height of the parallelogram is 6 inches.
Area of parallelogram = 10 * 6 = 60 square inches.
Therefore, the total area of the quadrilateral is the sum of the areas of the triangle and the parallelogram:
Total area = 18 + 60 = 78 square inches.
So, the area of the quadrilateral is 78 in.2.