Interior angles in a triangle add up to 180˚. Triangles close triangleA polygon with three straight sides. have three sides, therefore they have three angles. Interior angles in a triangle sum to a ...

Everyone learns the number one rule about triangles in high school: the angles of a triangle add up to 180 degrees. But did you know that sometimes they don't? Triangles are much more interesting than ...

Before reading this guide, it may be helpful to read the guides from Module 1 on the properties of angles and the properties of 2D shapes. The sum of the angles inside any polygon can be found by ...