## Geometry: Common Core (15th Edition)

To find the length of a segment on a number line, subtract the smaller point from the bigger point. We start with MP: $M=-3$ and $P=6$. Subtracting the smaller one from the bigger one gives $3-(-6)=3+6=9$. For NQ, $N=3$ and $Q=12$. Subtracting the smaller one from the bigger one gives $12-3=9$ These segments are congruent because they have an equal length.