In the subjects of geometry and trigonometry, a linear pair of angles is any two adjacent angles formed together to add up to 180°, or π (pi) radians. This rule is also known as the linear pair ...

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 ...

Polygons can be regular or irregular in shape. A polygon is a closed 2D shape with at least three sides. A regular polygon is a polygon with all equal sides and angles. An irregular polygon is a ...