Answer:
it's a(n)=a(n-1)+a(n-2)
this is also known as Fibonacci sequence
0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
19.1 should be your answer
First box is EF.
Second box is segment congruence postulate.
Third box is segment additon postulate.
Fourth box is DF. For this one the last sentence basically gives you the answer.
Just so you know for the fourth I guessed on if it's DF lined or DF unlined. I made my educated guess on the fact that the last line doesn't have a line. I hope this helps, and please tell me if I got something wrong, or my explanation wasn't sufficent enough for you.
1st quadrant hope this helps!
When dividing by a multiple of 10, depending on if it's greater than 0, The decimal place would move. In this case, the decimal place in 34.5 would move more to the left making the answer 3.45.