In trapezoid $abcd$, the parallel sides $ab$ and $cd$ have lengths of 8 and 20 units, respectively, and the altitude is 12 units. points $e$ and $f$ are the midpoints of sides $ad$ and $bc$, respectively. what is the area of quadrilateral $efcd$ in square units?

1.

EF is the median of the trapezoid ABCD, thus

units.

2.

The median EF bisects the altitude into 2 segments of equal length 6 units.

Thus the height of trapezoid EFCD is 6, and its 2 bases have length 14 and 8 units.

3.

From the area of the trapezoid formula:

(square units)

66 square units