Answer:
Option d. 20 [tex]unit^{2}[/tex]
Step-by-step explanation:
After plotting data determined the appropriate model to approximate the area of polygon is
[tex]f(x)=x^{2}+2x+5[/tex], here x = length of the side of a polygon
We have to find the area of a polygon that has a side length = 3
[tex]f(3)=3^{2}+2*3+5[/tex]
= 9 + 6 + 5
= 15 + 5 = 20
Option d. 20 [tex]unit^{2}[/tex] is the answer.
