What is a line with two arrows called?

Related questions

1. What is line and angle?
2. What do arrows on a line mean?
3. How many degrees is a straight line?
4. What does PQ mean in Spanish?
5. What do 2 lines mean on a triangle?
6. What is TCP in real estate?
7. What is difference between line and straight line?
8. What are the 5 angles?
9. What is Angle ABC?
10. What is called a line?

Tags

1. #would
2. #impossible
3. #thickness
4. #simply
5. #point
6. #points
7. #having
8. #straight
9. #number
10. #infinite
11. #usually
12. #constructed
13. #forever
14. #extending
15. #remember
16. #infinitely
17. #arrow
18. #directions