Chapter 2, Problem 90CP

The following figure shows a triangle formed by the three vectors $\stackrel{\to }{\text{A}}$ , $\stackrel{\to }{\text{B}}$ , and $\stackrel{\to }{\text{C}}$ . If vector $\stackrel{\to }{\text{C}}$ is drawn between the midpoints of vectors $\stackrel{\to }{\text{A}}$ and $\stackrel{\to }{\text{B}}$ , show that $\stackrel{\to }{\text{C}}=\stackrel{\to }{\text{C}}/2$