## Calculus: Early Transcendentals 8th Edition

$\vec{AB}=\vec{DC}$ $\vec{DA}=\vec{CB}$ $\vec{DE}=\vec{EB}$ $\vec{CE}=\vec{EA}$
To match vectors, look for pairs of the same direction and magnitude. Pairs $\vec{AB}=\vec{DC}$ and $\vec{DA}=\vec{CB}$ are easy to spot by their unique direction and magnitudes. For inner pairs,$\vec{DE}=\vec{EB}$ and $\vec{CE}=\vec{EA}$. Vectors can only be equal when BOTH direction and magnitude are equal. $\vec{DE}$ and $\vec{EB}$ both point northeast and share the same magnitude. $\vec{CE}$ and $\vec{EA}$ both point northwest and share the same magnitude. These are your pairs.