Extra: The puzzle presented in this activity is called a “perimeter magic triangle of order three.” To extend it to a higher-order perimeter magic triangle start by drawing a new triangle.

Explore the triangle area formula, its derivation, and practical examples to master this essential geometric concept effortlessly.

The outside edge of a shape is known as the perimeter. Learn how to work out the perimeter of a 2D shape with this Year 4 article from BBC Bitesize.

Any triangle has between one and three lines that bisect both the area and the perimeter. We determine the conditions for each possible number. The College Mathematics Journal emphasizes the first two ...

This feature originally appeared on the site for the NOVA program Infinite Secrets. More on the method Archimedes' method finds an approximation of pi by determining the length of the perimeter of ...