What Are Some Geometry Formulas for Triangles?

By Staff WriterLast Updated Apr 3, 2020 5:17:26 PM ET

A triangle is a three-sided polygon where the sum of its interior angles equals 180 degrees. Some common formulas for triangles include perimeter, the total sum of its individual side lengths; area, one-half of the product of a triangle’s base and height; and angle calculations based on the Pythagorean Theorem.