Using Tikz and PgfPlots (3 of 8: Triangles) - YouTube
SOLVED: Two sides in a triangle are LaTeX: 22 cm and LaTeX: 33 cm long, respectively. The angle between them is LaTeX: cos^-1left(frac23 ight).cos − 1 ( 2 3 ) .
shapes - How can I draw a right triangle in LaTeX? - TeX - LaTeX Stack Exchange
Art of Problem Solving
RGB triangle | TikZ example
latex - Small triangle appear when changing the edge labelling in tikz - Stack Overflow