In Exercises $1-26,$ assume that the coordinates of the points $P$, $Q, R, S,$ and $O$ are as follows:
$$P(-1,3) \quad Q(4,6) \quad R(4,3) \quad S(5,9) \quad O(0,0)$$
For each exercise, draw the indicated vector (using graph paper and compute its magnitude. In Exercises $7-20$, compute the sums using the definition given on page $698 .$ In Exercises $21-26,$ use the parallelogram law to compute the sums.
$$\overrightarrow{O P}+\overrightarrow{O Q}$$