Let's denote the area of the shaded region as S.
Observation: Notice that the shaded region consists of 4 smaller quadrilaterals: APWV, PQRS, RTUC, and UVWD. Each of these smaller quadrilaterals is similar to the original quadrilateral ABCD.
Ratio of Areas: Since the sides of the smaller quadrilaterals are one-third the length of the corresponding sides of ABCD, their areas will be one-ninth the area of ABCD.
Calculating the Area of the Shaded Region: Therefore, the area of each smaller quadrilateral is 180/9=20.
So, the total area of the shaded region, S, is:
S=4∗20=80
Therefore, the area of the shaded region is 80.