Geometry Tutorial: Triangles, Congruency & Types. Posted: February 24, 2025 | Last updated: July 11, 2025. ... which applies to right triangles for determining the length of sides.

A small clay tablet from the site of Kish in Iraq reveals a student calculated the area of a triangle incorrectly 4,000 years ago. When you purchase through links on our site, we may earn an ...