What is the length of this line?

Answer:
I believe it is 9
Step-by-step explanation:
If you turn that into a triangle then find the area it is 9.
Hope this Helps!
Answer:
Think of it as a right triangle. You can use pythagorean theorem.
a^2 + b^2 = c^2
6^2 + 3^2 = c^2
36 + 9 = c^2
45 = c^2
sqrt45 = c
Step-by-step explanation: