Given the third term is 12 and the rate of change is 3. What is the first 5 terms ?

6, 9, 12, 15, 18

Step-by-step explanation:

If the third term is 12, then to find the first term subtract 3 twice (or just subtract 6) to get 6. To find the rest of the terms add 3 accordingly. The equation to find this would be:

a_n = 6 + (n-1)3

statement #3: proof- ang is congruent to ang ecd : angles are congruent.  

step-by-step explanation:

1: the missing angles in statement #3  

a.) acb  

reason- the reason why the answer is acb is because angle ecd and angle acb are both the same size *that's what the word congruent means this is really simple.  

2: the missing word in reason #3  

c.) vertical  

reason- the reason why the answer is vertical is because the angles in that diagram on figure 2 is slanted, which is vertical, and the e and a both lay on vertical lines. along with the other's, but e and a are the 2 main points you want to focus on. and c is kind of like your starting point, because c is for both angles, not just one.  

i hope that was and understanding.