Angles on a Straight Line: Sum to 180°

This GeoGebra example demonstrates that the sum of adjacent angles formed by multiple rays from a common point on a straight line always equals 180°. The core mathematical concept is the measure of a straight angle (180°) and the additive property of angles. Construction details: the Line command creates the base line, Segment commands build the rays, Angle commands label each angle, and Point commands define key vertices. Objects include points A, B, C, D, line a, segments e, f, g, h, angles α and γ, and text objects text1 and text2 that dynamically display angle measures and their sum. Suitable for middle school geometry lessons, this interactive tool helps students grasp supplementary angles and the invariant sum on a straight line, supporting exploratory learning of angle relationships.