Using Algebra to Find Complementary and Supplementary Angles

The Organic Chemistry Tutor

This math tutorial provides a clear, step-by-step guide on how to solve geometry problems involving complementary and supplementary angles using algebraic expressions. The video begins by defining the core concepts: complementary angles sum to 90 degrees, often forming a right angle, while supplementary angles sum to 180 degrees, forming a straight line or linear pair. The instructor demonstrates how to translate these geometric relationships into algebraic equations to solve for unknown variables. The video progresses through three distinct examples of increasing complexity. The first problem involves a right angle split into two parts, requiring students to set the sum of two expressions equal to 90. The second problem features a linear pair, where students must set the sum equal to 180. The final problem challenges students with three adjacent angles forming a straight line, reinforcing the concept that all parts of a straight angle must sum to 180 degrees, regardless of how many angles are involved. This resource is highly valuable for bridging the gap between geometry and algebra. It helps students understand that geometric figures provide the "rules" for setting up equations, while algebra provides the tools to solve them. Teachers can use this video to model the process of identifying angle relationships, combining like terms, solving linear equations, and substituting values back into expressions to verify answers.