Definition:Direction Angles

Definition

Let $\LL$ be a line embedded in a Cartesian $3$-space.

The direction angles of $\LL$ are the three positive angles that $\LL$ makes with the coordinate axes.

They are usually denoted $\alpha$, $\beta$ and $\gamma$ for the angles made with the $x$-axis, $y$-axis and $z$-axis respectively.

Also see

• Direction Cosines: the cosines of the direction angles

• Results about direction angles can be found here.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): direction angles
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): direction angles