Answer this correctly and explain your answer I’ll give you brainalist + 10 points

D

Step-by-step explanation:

Use triangle inequalities:

7+10>x

x+10>7

x+7>10

Solve these and the conclusion is that it needs to be greater than 3 but less than 17.

D) greater than 3 but less than 17

Step-by-step explanation:

The third side must be greater than the difference and smaller than the sum of the two other sides.

10-7=3

10+7=17

so the third side must be greater than 3 and less than 17

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.