State the triangle law of vector addiction

Let $\vec{a}$ and $\vec{b}$ be two vectors. If $\vec{a}$ is represented by side AB and $\vec{b}$ is represented by side BC, then their resultant vector $\vec{R}$ is represented by side AC.

$$\vec{R} = \vec{a} + \vec{b}$$

This can be visualized as:

• Start at point A.
• Draw vector $\vec{a}$ from A to B.
• From point B, draw vector $\vec{b}$ to point C.
• The resultant vector $\vec{R}$ is the vector from A to C.