Fundamentals of Physics Extended (10th Edition)

$c_{y}=110$ m
The individual moves are (meters understood as units) $\vec{a}=20\vec{i} + 60\vec{j},$ $\vec{b}=b_{x}\vec{i} - 70\vec{j},$ $\vec{c}=-20\vec{i} + c_{y}\vec{j},$ $\vec{d}=-60\vec{i} -70\vec{j},$ The resultant, $\vec{r}=\vec{a}+\vec{b}+\vec{c}+\vec{d}=-140\vec{i}+30\vec{j}$ So, (with meters understood as units) $60-70+c_{y}-70=30$ $c_{y}=30-60+70+70=110$ $c_{y}=110$ m