Answer:
31.8
Step-by-step explanation:
Add all of the sides up, 10.8 + 10.8 + 5.1 + 5.1
Upon this you'll have your answer.
As its a parallelogram, its both 2 sides have same length...
10.8×2+5.1×2=31.8
or
10.8+10.8+5.1+5.1=31.8
