It is a ray, you can tell because it goes on only on one side while a line segment would have two solid dots/finite points on both ends. :))
X = 5.
Pythagorus Theorem:
c^2 = b^2 + a^2
(13)^2 = (12)^2 + a^2
a = sqrt((13)^2 - (12)^2))
a = 5
Answer:
where is the figure. We cant answer if we dont have the figure