Triangle
triangle
$\triangle$
\triangle
triangle down
$\triangledown$
\triangledown
Adding "down" to the "\triangle" makes it point downward.
big triangle up
$\bigtriangleup$
\bigtriangleup
big triangle down
$\bigtriangledown$
\bigtriangledown
triangle left
$\triangleleft$
\triangleleft
Adding "left" to the "triangle" indicates that the triangle is facing towards the left side.
triangle left 2
$\lhd$
\lhd
The term "lhd" is an abbreviation derived from "left-hand diamond."
triangle right
$\triangleright$
\triangleright
Adding "right" to the "triangle" indicates that the triangle is facing towards the right side.
triangle right 2
$\rhd$
\rhd
The term "rhd" is an abbreviation derived from "right-hand diamond."
triangle left and underline
$\unlhd$
\unlhd
The "unlhd" is "underline" and "lhd".
triangle right and underline
$\unrhd$
\unrhd
The "unrhd" is "underline" and "rhd".
black triangle
$\blacktriangle$
\blacktriangle
Adding "black" to the "triangle," "down triangle," "left triangle," and "right triangle" indicates that these triangle symbols are filled in black.