File:Triangle-angles.svg - Wikimedia Commons

File:Triangle-labelled.svg - Wikimedia Commons

File:Triangle-with-an-unknown-angle-or-side.svg - Wikipedia

Special right triangle - Wikiwand

File:Triangle - angles.svg - Wikimedia Commons

File:3-7-8 triangle.svg - Wikibooks, open books for an open world

Image – Where is Geometry?

Thomsen's Theorem - Futility Closet

Vectors

File:Right Angle Triangle.svg - Wikipedia

File:Triangle - angles.svg - Wikimedia Commons

File:Triangle sides-de.svg - Wikimedia Commons

File:Triangle-labels.svg - Wikimedia Commons

File:Triangle-law-of-sines.svg - Wikimedia Commons

File:Triangle-exteriour-angle-theorem-2.svg - Wikimedia Commons

File:45° 45° 90° Special Right Triangle.svg - Wikipedia