Luckily for us, the diagram already divided this figure into separate polygons. What I will be explaining is basically the addition of the areas of all the separate polygons. The area of the uppermost triangle is:
1/2 x b x h
= 1/2 x 20 x 8
(the base is 20, because in a parallelogram, opposite sides are congruent)
=10 x 8
= 80 in. squared
The next polygon we will be taking the area of is the parallelogram with the base length of 20 and the height of 16.
Area = b x h
= 20 x 16
= 320 in. squared
Now all we have left to do is add the two areas to obtain the total area.
Total Area = 320 + 80 = 400 in. squared
we can use properties of functions to find this out
for 
if b is even, then the ends of the function go in the same directions (both up or both down)
if b is odd, then the ends of the function go in different directions (one up and one down)
if a is positive and b is even, then both ends point up
if a is positve and b is odd, then it goes from bottom left to top right
if a is negative and b is even, then both ends point down
if a is negative and b is odd, then it goes from top left to bottom right
given 
a=5>0
b=4 which is even
so it has both ends pointing up
bottom right graph is yo answer