Answer:
CE = 12
Explanation:
The triangles are similar triangle because they have base angles that are congruent (transversals of parallel lines) and their third angles are equal because they form vertical angles.
Since the triangles are similar, their side lengths are proportional to each other. Set up a proportion...
5/10 = x/8 (side with length of 5 corresponds to side with length of 10)
Now solve for x by cross multiplying
40 = 10x
4 = x
*They want the entire length of CE, so 8 + 4 = 12