Answer:
The area of the shaded region is 21.
Explanation:
Since point E lies halfway between AB and BC, the area of the shaded region (As) consists of two identical triangles with base equal to AB and height equal to half the measure of BC:

Where At is the area of each triangle.


We know AB=7 and BC=6, thus:

Simplifying:

Finally:


The area of the shaded region is 21.
Note the area of the shaded region is half the area of the rectangle.