## Elementary Geometry for College Students (6th Edition)

$NM = \frac{1}{3}a+\frac{1}{2}b$
We can find the length of NM: $NM = NB + BM$ $NM = (AB-AN)+BM$ $NM = (a - \frac{2}{3}a)+\frac{1}{2}b$ $NM = \frac{1}{3}a+\frac{1}{2}b$