Dollar Sign Math for Geometry¶

Mathematicians have been using LaTeX for decades. Now that the wider tech and scientific communities are working more often in markdown languages and creating their own equations, they use LaTeX and often call it Dollar Sign Math. Fortunately for math geeks, the wider adoption from the scientifi community has led to software like GeoGebra and D2L including a DSM equation editor as an option.

DSM Code for Common Geometry Objects¶

Segment

\(\overline{AB}\)

\overline{AB}

Angle

\(\angle ABC\)

\angle ABC

Measured Angle

\(\measuredangle ABC\)

\measuredangle ABC

Ray

\(\overrightarrow{AB}\)

\overrightarrow{AB}

Line

\(\overleftrightarrow{AB}\)

\overleftrightarrow{AB}

Triangle

\(\triangle ABC\)

\triangle ABC

Circle

\(\circ PR\)

\circ PR

Square (QED)

\(\square\)

\square

Perpendicular

\(\perp\)

\perp

Parallel

\(\parallel\)

\parallel

Degree Measure

\(90^\circ\)

\90^\circ

Congruent

\(\cong\)

\cong

Similar

\(\sim\)

\sim

Fraction

\(\frac{1}{2}\)

\frac{1}{2}

DSM Code for Common Relations¶

The relations on the keyboard work fine: equality and strict inequalities. For example, given real numbers \(x,y\), then either \(x < y\), \(x > y\) or \(x = y\). Here are three common relations we often use.

Greater than or equal to

\(\geq\)

\geq

Less than or equal to

\(\leq\)

\leq

Not equal to

\(\neq\)

\neq

DSM Code for Sets¶

Modern geometry uses set theory as part of the fundamental logic of the system. Lines are sets of points, etc.

Element of

\(A \in \overline{AB}\)

A \in \overline{AB}

Subset

\(\subset\)

\subset

Superset

\(\supset\)

\supset

Union

\(\cup\)

\cup

Intersection

\(\cap\)

\cap

Proper Subset

\(\subseteq\)

\subseteq

Proper Superset

\(\supseteq\)

\supseteq

DSM Code for Quantifiers and Implications¶

There exists

\(\exists\)

\exists

For every

\(\forall\)

\forall

Implies

\(\implies\)

\implies

Therefore

\(\therefore\)

\therefore