Answer:

Step-by-step explanation:
The blue line represent the full line length.
We can add the parted black segments together and set it equal to the line.





Answer:
13.9 sorry if I'm wrong just trying to help.
Step-by-step explanation:
first plug in your numbers
a*2+ b*2= c*2
12*12= 144
7*7=49
144+49= 193
square root of 193: 13.89244399
rounded to nearest tenth is 13.9