# Angle and Line Symbols

Written by Jerry Ratzlaff on . Posted in Nomenclature & Symbols for Engineering, Mathematics, and Science

This is a list of the most common angle and line symbols:

SymbolDefinitionExample
$$\triangle$$ triangle $$\triangle ABC$$
$$\angle$$ angle $$\angle ABC = 60^\circ$$
$$\measuredangle$$ measured angle $$\angle ABC = 60^\circ$$
$$\sphericalangle$$ spherical angle $$\angle AOC = 60^\circ$$
$$\overleftrightarrow {AB}$$ infinite line distance
$$\overline {AB}$$ line segment from A to B
$$\overrightarrow {AB}$$ start line at point A
$$\overset{\frown} {AB}$$ arc from A to B
$$|A-B|$$ distance between A and B $$|A-B| = 9$$
$$\parallel$$ parallel to $$\overline {AB} \parallel \overline {XY}$$
$$\nparallel$$ not parallel to $$\overline {AB} \nparallel \overline {XY}$$
$$\perp$$ perpendicular lines $$\overline {AB} \perp \overline {XY}$$