Answer:
The length of the segment AB is 18.8 cm or 1.88 dm
Step-by-step explanation:
<u><em>The question in English is</em></u>
Points A, B and C are collinear in this order. Find the length of the segment: a) AB, if AC = 20 cm, BC = 0.12 dm
we have that
----> by Addition segment postulate
substitute the given values in centimeters
Remember that

so


solve for AB

Convert to dm

therefore
The length of the segment AB is 18.8 cm or 1.88 dm
If I did my math correctly I believe your answer will be C. :)
Three and two eight one thousandths
5x6 = 30 divided in half because its a triangle
=15
2x3 = 6
15-6 = 9